• Like
Chemistry Slide
Upcoming SlideShare
Loading in...5
×

Chemistry Slide

  • 863 views
Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
863
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
51
Comments
0
Likes
3

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Figure 2.UN5 Summary: Structure of an atom
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Figure 2.2 Chemical composition of the human body by weight.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Figure 2.6 Electron transfer and ionic bonding. (Step 2)
  • RIGHT CLICK FOR CONTROLS TO REWIND AND PLAY
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • RIGHT CLICK FOR CONTROLS TO REWIND AND PLAY
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students with limited backgrounds in chemistry and physics might struggle with basic concepts of mass, weight, compounds, elements, and isotopes. It may also be early in the semester when mature study habits have not yet developed. Consider passing along basic studying advice and tips to help students master these early chemistry concepts. In-class quizzes (graded or not) or a few homework problems will also provide reinforcing practice. 2. Students with limited backgrounds in chemistry will benefit from a discussion of Figure 2.5 and the differences and limitations of diagrams of atomic structure. The contrast in Figure 2.5 is a good beginning of such a discussion. In addition to comparing how the positions of electrons are depicted, note the problems with the sense of scale as indicated in the Figure 2.5 legend. 3. The dangers posed by certain chemicals in our food and broader environment often misleads people to associate c h emicals with harm. People might not want c h emicals added to their food or in their environment. Students often fail to appreciate the chemical nature of our bodies and our world and the potential harm or benefits of naturally occurring chemistry. They often fail to understand why n a tural does not necessarily mean f o od. (Consider presenting a long list of naturally occurring toxins to make this point.) Your class may benefit from a class discussion of these misconceptions about our attitudes towards c h emicals. 4. The half-lives of many radioactive substances, especially those used for dating fossils, might lead some students to expect very long periods of decay for any radioactive substance. This might even be alarming if students are someday asked to consume a radioactive substance for a medical test. However, some medically significant isotopes have relatively short half-lives. Radioactive iodine-131 is often used to diagnose or treat certain thyroid problems. Its half-life of eight days means that it will decay quickly. Teaching Tips 1. Students might be interested in the following aside: One of the challenges of raising captive, exotic animals is meeting the unique dietary requirements of the species. A zoo might have trouble keeping a particular animal because science has not fully determined what trace elements the animal requires. 2. Many breakfast cereals are fortified with iron. A person can crush the cereal and extract distinct iron particles with a magnet. An overhead projector or video imagining device should clearly reveal the iron particles stuck to the magnet. This short practical demonstration can help connect an abstract concept to a concrete example. 3. Here is a comparison that helps make the point about the differences in mass of protons and electrons. If a proton is as massive as a bowling ball, an electron will be the mass of a Lifesaver. (This is calculated by considering a 15-pound bowling ball, a Lifesaver with a mass of 0.12 ounces, and the textbook’s formula that an electron is 1/2,000 the mass of a proton.) 4. Have your students try to calculate the number of covalent bonds possible for a variety of atoms. Then provide the students with a list of elements and the number of outer electrons for each and have them make predictions about the chemical formula for many types of molecules. 5. Consider challenging your students to suggest relationships in human lives that are analogous to each of the three types of chemical bonds discussed. Evaluating the accuracy of potential analogies requires careful analysis of the chemical bonding relationships. Small groups might provide immediate critiques before passing along analogies for the entire class to consider.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • RIGHT CLICK FOR CONTROLS TO REWIND AND PLAY
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Figure 2.10 Cohesion and water transport in plants.
  • RIGHT CLICK FOR CONTROLS TO REWIND AND PLAY
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Figure 2.14 A crystal of table salt (NaCl) dissolving in water.
  • Figure 2.14 A crystal of table salt (NaCl) dissolving in water.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.
  • Student Misconceptions and Concerns 1. Students are unlikely to have carefully considered the four special properties of water that are apparent in our lives. However, these properties are of great biological significance and are often familiar parts of our lives. The connections between these properties and personal experiences can invest great meaning into a discussion of water’s properties. A homework assignment asking for three examples of each of these properties in each student’s experiences will require reflection and potentially produce meaningful illustrations. Similarly, quizzes or exam questions matching examples of each property to a list of the properties requires high-level evaluative analysis. 2. Students at all levels struggle with the distinction between heat and temperature. Students might also expect that all ice is about the same temperature, 0˚C. Redefining and correcting misunderstandings often takes more class time and energy than introducing previously unknown concepts. Teaching Tips 1. Here is a way to have your students think about the s t icky nature of water in their lives. Ask them to consider the need for a towel after a shower or a bath. Once we get out of the shower or bath, we have left the source of water. So why do we need the towel? The reason we need a towel to dry off is that water is still clinging to our bodies because water molecules are polar. The molecules on cell surfaces are also polar, so our skin and the water both s t ick to each other. 2. Some students may be intrigued if you tell them that you too can stand on the surface of water— when it is frozen . Thus, it is necessary to note a liquid water surface when talking about surface tension. 3. Have students compare the seasonal ranges of temperatures of Anchorage and Fairbanks, Alaska. (Many websites, such as Yahoo, provide weather information about various cities.) These two northern cities have large differences in their annual temperature ranges. Make the point that the coastal location of Anchorage moderates the temperature. 4. Several versions of the following analogy are easy to relate to students. (a) Ask students how the average on an exam would be affected if the brightest students didn’t take the test. (b) The authors note that the performance of a track team would drop if the fastest sprinters didn’t compete. In both analogies, removing the top performers lowers the average just as the evaporation of the most active water molecules cools the evaporative surface. 5. I t is not the heat, it is the humidity. The efficiency of evaporative cooling is affected by humidity. As humidity rises, the rate of evaporation decreases, making it more difficult to cool our heat-generating bodies on a warm and humid summer day. 6. Ask your students if the ocean levels would change if ice didn’t float. They can try this experiment to find out. Place several large chunks of ice in a glass and fill the glass up completely with water to the top rim. Thus, the ice cubes should be sticking up above the top of the filled glass. Will the glass overflow when the ice melts? (No.) This phenomenon is important when we consider the potential consequences of global warming. If floating glaciers melt, ocean levels will not be affected. However, if the ice over land melts, we can expect increased ocean levels. 7. The Environmental Protection Agency (EPA) website (www.epa.gov/acidrain/education/) includes good information about acid precipitation and teaching ideas. 8. The SETI (Search For Extraterrestrial Intelligence) Institute’s Mission is t o explore, understand and explain the origin, nature, and prevalence of life in the universe (www.seti.org). Your students might enjoy exploring this respected scientific organization.

Transcript

  • 1. Chapter 2 Essential Chemistry for Biology 0
  • 2.  
  • 3. Start with Atoms
      • Atoms
        • Fundamental building blocks of matter
        • Composed of three smaller subatomic particles
          • Positively charged _______________
          • Uncharged (neutral) _______________
          • Negatively charged _______________
        • # _______________ = # _______________
        • Protons and neutrons are part of the nucleus
        • Electrons move around the nucleus
  • 4. Nucleus Protons Neutrons Electrons Nucleus Cloud of negative charge  2 electrons  2 2 2
  • 5. Proton • Positive charge • Determines element Neutron • No charge • Determines isotope Electron • Negative charge • Participates in chemical reactions • Outer-shell electrons determine chemical behavior Nucleus • Consists of neutrons and protons Atom
  • 6. Elements
      • A pure substance consisting of atoms with the same number of protons
      • _______________ _______________ = quantity of protons (unique for each element)
        • Ex: Carbon = 6
    Mercury  Hg  Copper  Cu  Lead  Pb 
  • 7. H Rb K Na Li Fr Cs Sr Ca Mg Be Ra Ba Y Sc Ac La Zr Ti Rf Hf Nb V Db Ta Mo Cr Sg W Tc Mn Bh Re Ru Fe Hs Os Rh Co Mt Ir Pd Ni Uun Pt Xe Kr Uuo Rn Ag Cu Uuu Au Cd Zn Uub Hg Ar Ne In Ga Tl Al B Sn Ge Uuq Pb Si C Sb As Bi P N Te Se Uuh Po S O I Br At Cl F He Th Ce Pa Pr U Nd Np Pm Pu Sm Am Eu Lr Lu Cm Gd Bk Tb Cf Dy Es Ho Fm Er Md Tm No Yb 6 C 12
  • 8. Elements
      • There are 92 naturally occurring elements on Earth.
      • 25 elements are essential to life.
      • Four elements make up about 96% of the weight of the human body:
        • Oxygen
        • Carbon
        • Hydrogen
        • Nitrogen
  • 9. Carbon  C  : 18.5% Hydrogen  H  : 9.5% Nitrogen  N  : 3.3% Calcium  Ca  : 1.5% Trace elements: less than 0.01% Boron  B  Manganese  Mn  Oxygen  O  : 65.0% Magnesium  Mg  : 0.1% Phosphorus  P  : 1.0% Potassium  K  : 0.4% Sulfur  S  : 0.3% Sodium  Na  : 0.2% Chlorine  Cl  : 0.2% Cobalt  Co  Chromium  Cr  Iron  Fe  Iodine  I  Fluorine  F  Copper  Cu  Silicon  Si  Zinc  Zn  Vanadium  V  Tin  Sn  Molybdenum  Mo  Selenium  Se 
  • 10. Trace Elements
      • Occur in smaller amounts and are essential for life
      • Deficiencies cause disease
        • Example: An Iodine deficiency causes goiter
  • 11. Isotopes
      • Atoms of the same element that differ in the number of neutrons
      • Example : 12 C (6p and 6n), 13 C (6p and 7n), 14 C (6p and 8n)
      • _______________ _______________ = protons plus neutrons
  • 12. H Rb K Na Li Fr Cs Sr Ca Mg Be Ra Ba Y Sc Ac La Zr Ti Rf Hf Nb V Db Ta Mo Cr Sg W Tc Mn Bh Re Ru Fe Hs Os Rh Co Mt Ir Pd Ni Uun Pt Xe Kr Uuo Rn Ag Cu Uuu Au Cd Zn Uub Hg Ar Ne In Ga Tl Al B Sn Ge Uuq Pb Si C Sb As Bi P N Te Se Uuh Po S O I Br At Cl F He Th Ce Pa Pr U Nd Np Pm Pu Sm Am Eu Lr Lu Cm Gd Bk Tb Cf Dy Es Ho Fm Er Md Tm No Yb 6 C 12
  • 13. Radioactive Isotopes
      • _______________ – atoms with the same # protons, but different # neutrons
      • Radioactive isotopes are not stable
        • Nucleus (protons and neutrons) spontaneously decays into other elements and electrons are emitted
      • Can be used as tracers and attached to molecules
        • Example: Attach a tracer to glucose to monitor brain activity (PET scan)
  • 14. Positron-Emission Tomography (PET) Scan
  • 15. Electron Arrangement and the Chemical Properties of Atoms
      • Atoms acquire, share and donate electrons
      • Some atoms do so easily, others do no
        • The number and arrangement of electrons in atoms dictate acquisition, sharing and donation
  • 16. Electrons and Energy Levels
      • Atoms have the same # electrons as protons
      • Electrons orbit the nucleus of an atom in specific electron shells
      • The farther an electron is from the nucleus, the greater its energy
      • The number of electrons in the outermost shell determines the chemical properties of an atom
  • 17. Shell Models First electron shell  can hold 2 electrons  Outer electron shell  can hold 8 electrons  Hydrogen  H  Atomic number = 1 Carbon  C  Atomic number = 6 Nitrogen  N  Atomic number = 7 Oxygen  O  Atomic number = 8 Electron
  • 18. Electron Interactions
      • Atoms whose outermost shell is not completely full tends to interact with other atoms
        • They donate, accept, or share electrons to eliminate vacancies
        • Those with the outermost shell filled are chemically inactive and very stable
    sodium 11p+ , 11e - chlorine 17p+ , 17e - argon 18p+, 18e -
  • 19. Electrical Charge
      • An atom with equal numbers of protons and electrons has no net charge
      • _______________ are atoms that carry a charge
        • Have either gained (negatively charged) or lost (positively charged) electrons
  • 20. Sodium atom 11p + 11e - no net Charge (weakly electro- negative) Sodium ion 11p + 10e - net positive charge electron loss Chlorine atom 17p + 17e - no net Charge (highly electronegative) Chlorine ion 17p + 18e - net negative charge electron gain
  • 21. Molecules and Mixtures
      • Molecule – forms when > 2 atoms join in chemical bonds
      • Chemical Bond – attractive force between atoms due to interactions of electrons
      • Compounds – molecules consisting of > 2 elements (Ex: water is 2H bound to 1O)
      • Mixture – elements intermingle but do not bind (Ex: Sugar into water – sugar dissolves, no bonds formed)
  • 22. Chemical Bonding and Molecules
      • Chemical reactions enable atoms to donate, acquire or share electrons to complete their outer shells.
      • Chemical reactions usually result in atoms interacting through three types of bonds
        • Ionic bond
        • Covalent Bond
        • Hydrogen Bond
  • 23. Ionic Bonds
      • Strong association between a positive ion and a negative ion (attraction of opposite charges)
  • 24. Outer shell has 1 electron Outer shell has 7 electrons The outer electron is stripped from sodium and completes the chlorine atom’s outer shell Na Sodium atom Cl Chlorine atom Complete outer shells The attraction between the ions—an ionic bond—holds them together Na  Sodium ion Cl  Chlorine ion Sodium chloride (NaCl)
  • 25. See Animation on Ionic Bonds (Posted to MyCourses)
  • 26. Covalent Bonds
      • Form when two atoms share > 1 pairs of outer-shell electrons
      • _______________ covalent bond
        • Atoms share electrons equally
      • _______________ covalent bond
        • Electrons are shared unequally
        • Produces polar molecules – one end slightly negative, other slightly positive
  • 27. Two hydrogen atoms, each with one proton, share two electrons in a single nonpolar covalent bond . Molecular hydrogen (H—H) Two oxygen atoms, each with eight protons, share four electrons in a nonpolar double covalent bond . Molecular oxygen (O=O) Two hydrogen atoms each share an electron with an oxygen atom in two polar covalent bonds . The oxygen exerts a greater pull on the shared electrons, so it has a slight negative charge. Each hydrogen has a slight positive charge. Water molecule (H—O—H)
  • 28. See Animation on Covalent Bonds (Posted to MyCourses)
  • 29. Hydrogen Bonds
      • Attraction between a _______________ atom and another atom
        • Both have their own separate covalent bonds
      • Are not chemical bonds
        • Do not make atoms into molecules
        • Weaker than ionic or covalent, and easily form or break
        • Used to stabilize structures of large molecules
  • 30. Hydrogen Bonds
      • Water is a compound in which the electrons in its covalent bonds are shared unequally.
        • This causes water to be a polar molecule , one with opposite charges on opposite ends.
    2 H 2 2 H 2 O O 2 Hydrogen gas Oxygen gas Water  
  • 31. Hydrogen Bonds
      • The polarity of water results in weak electrical attractions between neighboring water molecules.
        • These interactions are called hydrogen bonds .
    Hydrogen bond
  • 32. Water – The Most Important Molecule
      • Without water, there would be no life
      • Life on Earth began in water and evolved there for 3 billion years
        • Modern life remains tied to water
        • Your cells are composed of 70%–95% water
      • The abundance of water is a major reason Earth is habitable
  • 33. Polarity of the Water Molecule
      • Water molecules are polar
        • Form hydrogen bonds with each other and with other polar molecules
        • Hydrophilic (water-loving) substances are polar
        • Hydrophobic (water-dreading) substances are nonpolar (ex. Oils)
    + + H H O - − slight negative charge on the oxygen atom The positive and negative charges balance each other; overall, the molecule carries no charge. slight positive charge on the hydrogen atoms
  • 34. See Animation on Water Structure (Posted to MyCourses)
  • 35. Water’s Life-Giving Properties
      • The polarity of water molecules and the hydrogen bonding that results explain most of water’s life-supporting properties:
        • Water molecules stick together.
        • Water has a strong resistance to change in temperature.
        • Frozen water floats.
        • Water is a common solvent for life.
  • 36. The Cohesion of Water
      • Hydrogen bonding provides _______________ (resistance of molecule separation)
  • 37. Microscopic tubes Cohesion due to hydrogen bonds between water molecules Evaporation from leaves drives the flow of water up and through the plant SEM Flow of water
  • 38. See Animation on Water Transport (Posted to MyCourses)
  • 39. Water Moderates Temperature
      • Because of hydrogen bonding, water has a strong resistance to temperature change.
      • Heat and temperature are related, but different.
        • _______________ is the amount of energy associated with the movement of the atoms and molecules in a body of matter.
        • _______________ measures the intensity of heat.
      • Water can absorb and store large amounts of heat while only changing a few degrees in temperature.
  • 40.
      • Earth’s giant water supply causes temperatures to stay within limits that permit life.
      • Evaporative cooling removes heat from the Earth and from organisms.
  • 41. The Biological Significance of Ice Floating
      • When water molecules get cold enough, they move apart, forming ice.
      • A chunk of ice has fewer molecules than an equal volume of liquid water.
      • Ice floats because it is less dense than the liquid water around it.
    Hydrogen bond Liquid water Ice
  • 42.
      • If ice did not float, ponds, lakes, and even the oceans would freeze solid.
      • Life in water could not survive if bodies of water froze solid.
    The Biological Significance of Ice Floating
  • 43. Water as the Solvent of Life
      • A _______________ is a liquid consisting of a homogeneous mixture of two or more substances.
        • The dissolving agent is the _______________ .
        • The dissolved substance is the _______________ .
      • When water is the solvent, the result is an aqueous solution .
  • 44. Sodium ion in solution Chloride ion in solution Salt crystal Na  Na  Cl – Cl –
  • 45. Solvents form “ spheres of hydration ” around solutes
  • 46. Acids, Bases, and pH
      • Ions are dissolved in fluids both inside and outside each living cell
      • _______________ ions are the most influential
        • Chemically active
        • Tons of them – they are everywhere
  • 47. How do Acids and Bases Differ?
      • A chemical compound that releases H + to solution is an _______________ .
      • A compound that accepts H + and removes it from solution is a _______________ .
    Basic solution Neutral solution Acidic solution
  • 48. Acids, Bases, and pH
      • pH scale
        • Indicates hydrogen ion (H + ) concentration of a solution
        • Ranges from 0 (most acidic , most H + ) to 14 (most basic or alkaline , least H + )
        • At pH 7 ( neutral ) H + and OH - concentrations are equal
    Neutral Basic Acidic pH scale 14 7 0 Lower H + concentration H + = OH – Greater H + concentration
  • 49. Buffers Against Shifts in pH
      • Enzymes and biological molecules function properly only in a narrow range of pH
      • Cells must quickly respond to pH shifts otherwise cellular processes halt
      • Most cells and body fluids are buffered in order to maintain a constant pH
  • 50.
      • A set of chemicals (an acid or base AND its salt) that keeps the pH of a solution stable
      • A “salt” is any compound that dissolves easily in water, and releases ions other than H + and OH -
        • Form when an acid interacts with a base (Ex: NaCl)
        • HCl + NaOH NaCl + H 2 0
        • Na + + Cl - + H 2 O
    Buffer System
  • 51.
      • Buffers help maintain homeostasis
      • Most biological processes proceed only within a narrow pH range, usually near neutrality (blood pH = 7.3 – 7.5)
        • Acidosis: decline in blood pH
        • Alkalosis: increase in blood pH
        • Both are potentially lethal
    Functions of Buffer Systems
  • 52. Evolution Connection: The Search for Extraterrestrial Life
      • If life similar to ours has evolved elsewhere in the universe, then it too would depend upon water.
      • Recent NASA missions to Mars have detected evidence that liquid water flowed over the planet’s surface.