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Your title pagefor Topic 3:KnowledgeBuilding onMatter andChemistry
Yourdivider forknowledgesection
Grade 8 Vocabulary List (Knowledge Building on Matter and                           Chemistry)  1. physical property  2. c...
________________________________________________________                       (Summary Note for Chapter 6, Section 1)____...
The periodic table arranges the elements into rows called ____________________and columns called__________________________...
electrons when they react. And it gets easier for them to react as you farther down the column becausethese elements have ...
DOT DIAGRAMS – Exercise 1Using a periodic table or electron configuration, place dots around the following elementsymbols ...
Dot Diagrams- Exercise 2 – Handout
________________________________________ (Chapter 6 Section 2)                (Our first background note for What is in Ta...
2. When the 2 elements to form an ionic bond are ______________ elements, a ______________________________________ occurs....
and a negative part and is a polar molecule. In turn, in tap water, the water molecules tend be attractedto one another (i...
SUMMARY – Organizer Handout for Chapter 5, Section 1Step 1: Read one time.          * Take notes too if you want!        ...
Supporting Details 2 (1+ sentences)_______________________________________________________________________________________...
__________________________________________________________________________________________________________________________...
SUMMARY – Organizer Handout for Chapter 5, Section 2Step 1: Read one time.          * Take notes too if you want!        ...
Supporting Details 2 (1+ sentences)_______________________________________________________________________________________...
__________________________________________________________________________________________________________________________...
Chemistry in a BowlPart 1 - InvestigationsMaterials:            plastic bowl (x3)            2 plastic spoons          ...
Procedure 4 (Teacher and Student Demonstration)   1. After you have discussed what happened in the three bowls, the teache...
4)   This equation tells us what chemical reaction happened in procedure 3 when the vinegarwas added to the baking soda. I...
________________________________________________                    (Summary Note for Chapter 7, Section 1)As you learned ...
Reactant 1 + Reactant 2 + … etc +  Product 1 + Product 2 … etc. + energy (a reaction whereenergy is released)Reactant 1 +...
Now the equation above is balanced and proper.________________________- How do we actually know which elements are actuall...
Balancing Equations Worksheet      A. Write the correct coefficients to balance each equation below1)      ____ Na3PO4 + _...
Chemical Reactions and Equations Practice – Worksheet 2Part A: Identify the following parts of each chemical formula by ci...
Part D: Balance each of the following equations following the procedure described in class.Be sure to show your work.P + O...
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Transcript of "Kb on Matter and Chemistry knowledge handouts and notes"

  1. 1. Your title pagefor Topic 3:KnowledgeBuilding onMatter andChemistry
  2. 2. Yourdivider forknowledgesection
  3. 3. Grade 8 Vocabulary List (Knowledge Building on Matter and Chemistry) 1. physical property 2. chemical property 3. physical change 4. chemical change 5. density 6. state (as with matter) 7. reactivity 8. reaction (chemical) 9. chemical equation 10. endothermic 11. exothermic 12. salt 13. electron 14. chemical bond 15. ion 16. molecule 17. activation 18. concentration 19. inhibitor 20. catalyst 21. enzyme 22. substance 23. heterogeneous 24. homogeneous 25. solution 26. aqueous 27. saturated 28. acid 29. base 30. pH** Need to write for each word:1. Definition2. Your own sentence
  4. 4. ________________________________________________________ (Summary Note for Chapter 6, Section 1)__________________________________________________-Recall that an atom is the basic unit of any chemical element. It consists of a core centre containing oneor more protons and also one or more neutrons. This centre also represents most of the atom’s massand so the rest of the atom is pretty much empty space….except for one other very important particle(especially for chemical reactions), the ___________________________.What is an electron? Where is the electron? What is different about the electrons in each differentelement? These are all important questions for you to understand and this section of your textbook willhopefully help you to understand.____________________________________? ___________________________________?An ______________________ is another stable subatomic particle found in an atom and it has anegative charge.The electron is found outside of the atom’s core centre floating around in the space beyond called the_________________________. However, the electrons in the atom, are NOT free to float aroundanywhere they want. Rather, scientists believe there exists a _________________________________that can predict where you will find each and every electron. And this pattern or model involves thepresence of special areas called ___________________________________.More specifically, it is currently believed energy levels are similar to planet orbits. Each of them is onecircular area that surrounds the atom’s core. So they stack up on one another so that the closest energylevel is the smallest and then each additional energy level will be slightly bigger and bigger as they arefurther and further away. (Again just like a series of planet orbits). See figure 3 in your textbook.Now, it is further believed that each energy level can contain a ________________________ ofelectrons. The first energy level can hold up to 2 electrons. The second energy level can hold up to 8electrons. The third energy level can hold up to 32 electrons. There is actually a mathematical sequencein effect here. The maximum number of electrons in any energy field can be determined using the_____________________. n refers to the energy level. So for instance, the 5th energy level can hold upto 2(5)2 or 50 electrons. You can then see that that the farther an energy level is from the nucleus, themore maximum number of electrons it can hold in an exponential fashion.___________________________________________________________________?Further, how many electrons are actually in each of the levels depends on the specific element. Forinstance, hydrogen holds only one electron in the first energy level but magnesium holds 2 in the first, 8in the second and then 4 in the third for a total of 12 electrons.There is actually a ____________________________ of electrons (and also protons) in each elementsuch that we can __________________the elements according to their number of electrons (or protons).And we can see such an ordering or electron configuration on the ______________________________.
  5. 5. The periodic table arranges the elements into rows called ____________________and columns called_____________________________. The element in the first row and first column, hydrogen, has only 1electron. As you go _________________ a period or onto the next period (when you get to a period’send), each next element has ____________________________ (and proton). So, helium has 2electrons. Similarly in the second period, lithium has 3 electrons, beryllium has 4 electrons, boron has 5electrons etc._________________________________________________________-There are also other special patterns and in turn characteristics that result for certain elements that holdso many electrons. Notice on the periodic table, that all elements in any particular column (ie. family orgroup) have the ___________________________ of electrons in their outer most (or final) energy level.For instance, in the group 1 (ie. column 1), all the elements in this family have exactly one electron intheir outer most energy levels. (Hydrogen has 1 in its first and only energy level. Lithium also has justone l electron is its second and final energy level. Sodium has just one electron in its third and finalenergy level as well. Etc.This is ____________ a coincidence. Because elements in any family or group (ie. column) of the periodtable all contain the same number of electrons in their outer most energy level, they also share manyspecific if not unique characteristics.The first important characteristic is __________________________. If an element has the_______________________of possible electrons in its most outer energy level, it is considered to bevery _____________________ (ie. they do not react with other thing very well). Thus, the elements ingroup (column) 8, are all stable elements. Notice, helium which has the maximum number of electrons infirst and only energy level is a stable element. Similarly, neon has eight in its second and final energylevel and is stable too. Likewise, argon has its third and final energy level filled up with the maximumnumber of 18 electrons and is stable as well. These stable elements are also called noble elements andare all gases. We can also call this group of elements, the _____________________________. Besidesbeing stable or inert gases, they can also produce coloured light if an electric current is passed throughthem. You have probably seen many neon signs before.Another important (opposite) characteristic is ____________________. Elements can also react moreeasily or less easily depending on the number of electrons they have and how many electrons they havemore or less than the nearest stable element. All elements “wish” to be stable like the noble elements.Elements can pick up electrons when they react with other things. In general, it is ______________ to__________________________ to elements with _______________________ and ______________for them to _____________________. This is because, as negative electrons get closer to the nucleus,they are more greatly attracted with having opposite charges from the positive protons.Consider the ____________________ family. These elements are in group 17 and all are missing oneelectron to have the maximum number of electrons in their outer energy levels (ie. they have 7electrons). As a result, they are ______________________. These elements need just one electron andare “so close” to “getting their wish”. We also find that the elements higher up in the family are the mostreactive because they have fewer number of energy levels with electrons. It is easier then for theseelement to pick up electrons because their outer most energy levels are closer to the nucleus and soadditional electrons can be easily attracted. Thus, fluorine is extremely reactive whereas iodine is lessreactive.To give another example, we have the __________________ family in the first column. These elementsall have just one outer energy level electron. They are all metals. They need to lose just one electron tohave a stable number of electrons like the nearest noble element. Thus it is easy for them to lose
  6. 6. electrons when they react. And it gets easier for them to react as you farther down the column becausethese elements have more energy levels which are farther away from the nucleus and thus theirelectrons are not as attracted and are more easy to remove.________________________________-It is also useful to use special diagrams to illustrate different elements and their number of electrons.The electron dot diagram is one way. It shows the __________________ for the element and then_____________for the ____________________ that_____________________________________________. Dots are written one at a time in a clockwisedirection on four sides of the symbol. Additional dots are then added to make a pair in the same way.See figure 9 in your textbook for some examples. These diagrams are useful to show how elementsbond through their electrons with each other. (You will learn more in a later lesson).
  7. 7. DOT DIAGRAMS – Exercise 1Using a periodic table or electron configuration, place dots around the following elementsymbols to represent the number of electrons in the outer shell. 1. Li 11. Ar 2. C 12. K 3. O 13. C 4. F 14. Ti 5. Ne 15. Ni 6. Na 16. As 7. Al 17. Br 8. P 18. Kr 9. S 19. Rb 10. Cl 20. Sr
  8. 8. Dot Diagrams- Exercise 2 – Handout
  9. 9. ________________________________________ (Chapter 6 Section 2) (Our first background note for What is in Tap Water)Right now we are considering the question, “What is in tap water?”. There are many way you couldanswer this question. There are chemicals. There is dirt. There are perhaps viruses. However, from achemistry perspective, you could also zoom into even the smaller things that make up the chemicals, dirtor even viruses in the water. That is you could look at the makeup of the elements in the tap water.Do various elements just float around in tap water? What (medium) are they actually floating around inwhen we say they are floating in (tap) water. Well, the floating elements and even the “basic medium” forwater (ie. water molecules) are really (well most often) just different combinations of elements that areable to form very tight bonds with each other in specific ways (similar to puzzle pieces locking in witheach other. As you will see later for instance, the basic medium of water (water molecules) is just arepeating pattern of 2 hydrogen elements bonding to one oxygen element to make a _______________.But ___________ does bonding happen between elements in water (or any other kind of matter)?The simple answer… elements form bonds with other elements to make ____________________ (ie.matter having at least 2 elements bonded together) by using their electrons in their outer most energylevels. There are 2 basic ways that they can do this:A. _________________________- in this case, elements form bonds by losing or gaining electrons. Thegeneral idea is one element loses its electrons and another (or other) element(s) gain the electrons. Andwhen they lose or gain the electrons, they become tightly associated with each other that they do notwant to easily break away. So we say the elements have bonded._____________ do elements lose or gain electrons? In the last lesson you learned that the noble gasesare very stable and do not react. Other elements however are usually more reactive because they arenot stable but want to become stable like the noble gases. So, by losing or gaining one or more electron,the atoms can then have a number of electrons that matches a noble gas’ configuration. And then theseatoms are so “happy” in this state that they do not easily separate. In other words,they__________________ to each other.Example 1 – Sodium (Na) will easily bond with Chlorine (Cl) to make Sodium Chloride (NaCl) or tablesalt. Consider that sodium has one more electron than the nearest stable element, helium. Thus, if it________________ one electron, it will become like helium in terms of the number of electrons. At thesame time, chlorine has one less electron than the nearest noble gas, argon. So, it needs to_____________ one electron to have the same number as argon. Hence, when Na and Cl come closeto each other, they are instantly attracted. Na loses one electron and Cl gains the electron. Then, theystay close together because they are very “happy” (ie. stable) in this state. See Figure 13 for diagram.Example 2 – Similarly, magnesium will ________________ electrons to become like Neon and giveeach electron to one chlorine as both would like to gain one electron. In other words, 2 magnesiumatoms will easily bond with 2 chlorine atoms to make Magnesium Chloride (MgCl2). (Notice we write 2as a subscript to show the resulting bond) See figure 14 for a useful diagram.* Also, see page 177 for information on writing chemical shorthand.Other Notes –1. Whenever an element loses or gains one or more electrons, it gains either a positive or negativecharge because electrons are negative themselves. And we call it an ____________. This means anatom like Sodium that loses them becomes a positive ion. Similarly, when chlorine gains electrons, itbecomes a negative ion. We also call the bond them form an _____________________.
  10. 10. 2. When the 2 elements to form an ionic bond are ______________ elements, a ______________________________________ occurs. More specifically, 2 different metal elements alone don’t normally bond.Rather hundreds of one metal atom associate with hundreds of the other metal atom. Then each atombecomes an ion by losing or gaining an electron. But each positive ion does not give its electron to justone other negative ion. Rather, the electrons are passed around through all of the participating atoms.So each, negative ion will gain an ion but not always the same one. This also helps to explain why it ishard to break metal into pieces with a hammer because the elements can “grab” other electrons andstay together. See figure 15.B. _________________________- in this case, 2 or more different elements do not give up or takeelectrons to form bonds. Instead, they __________________ them. The reason why this happens isbecause certain elements would have to give up or take too many electrons to become like the nobleelements. So it is easier just to share and an electron from each element then gets used by both of themto make each atom have a more stable electron configuration. When 2 elements share an electron, wesay a _________________________ is formed. Also, when only one electron is shared from eachelement, we call the bond a single bond. When 2 electrons are shared from each element, we call thebond a double bond. Triple bonds are next etc.Example – Carbon will react (form a bond) with 2 oxygen atoms by sharing 4 of its electrons. Morespecifically, two electrons from each of the oxygen atoms is shared with carbon so that carbon can have4 more electrons and be like neon. Similarly, two of carbon’s electrons is shared with one of the oxygenatoms so that the oxygen can have 8 electrons and be stable like helium too. Similarly, another two ofcarbon’s electrons get shared with the other oxygen to make it stable too. We write this compound asCO2 to note that 2 oxygen atoms bond with one carbon. See figure 17.More simple examples involve hydrogen forming a single bond with another hydrogen to make H2.Nitrogen is similar but bonds with another nitrogen to form N2 by making 3 bond. (ie. each nitrogenshare 3 electrons).Notes –1. Whenever two or more elements form a covalent bond, the resulting compound is called a_____________________. Many molecules often associate together to create relatively large amountsof matter. So when you look at something like carbon dioxide you are really looking at hundreds ofcarbon dioxide molecules.2. When a covalent bond is formed, the electrons may be shared equally between the two elementsor not! When there is an equal sharing, we call the resulting a _______________________. A goodexample is H2 or N2 because the participating elements are the same and have equal sharing strength.On the other hand, bonding elements that different from each other often do not share the electronsequally. For example, in the case of HCl, Chlorine attracts the shared electrons________________________ than the hydrogen. As a result, one element will be slightly more negative(Ex. the chlorine) and the other element will be slightly more positive (ex. the hydrogen). In such a case,we call the resulting molecule a ___________________________.So again what is in Tap Water?From above you may realize now that tap water contains hundreds of water molecules Each watermolecule is really just H2O. That means, two hydrogen atoms are bonded to one oxygen. Also, eachhydrogen shares one electron with the oxygen and the oxygen then shares 2 electrons (one with eachhydrogen). So a covalent bond is formed. Also, the oxygen attracts the electrons more closely and isslightly negative. Each hydrogen atom becomes slightly positive. As a result, water has a positive part
  11. 11. and a negative part and is a polar molecule. In turn, in tap water, the water molecules tend be attractedto one another (ie. the positive part of one is attracted to the negative part of the other). As a result,water has an interesting property: it can be ____________________________ from other matter. This iswhy water is somewhat _____________________. For instance, it can stick to your clothes to makethem wet. As well, if you hold a negatively charged object like a balloon, you can make the water bend!The polar molecules also make it a little more __________________________ water molecule fromeach other. This helps to explain another property of water: ___________________________. Similar toa metal, a bunch of water molecules are slightly interlinked and so they are able to support things on top.This is why very light things (like insect) are able to walk on top of tap water’s surface.
  12. 12. SUMMARY – Organizer Handout for Chapter 5, Section 1Step 1: Read one time. * Take notes too if you want!  Reading NotesStep 2:Write the Main Idea (1-2 sentences) –______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Step 3: Write the supporting ideas. Write in the small boxes first!Step 4: Write the supporting details. Write in the bigger boxes later!Supporting Idea 1 (1-2 sentences)Supporting Details 1 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 2 (1-2 sentences)
  13. 13. Supporting Details 2 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 3 (1-2 sentences)Supporting Details 3 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 4 (1-2 sentences)Supporting Details 4 (1+ sentences)___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
  14. 14. _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 5 (1-2 sentences)Supporting Details 5 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 6 (1-2 sentences)Supporting Details 6 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________** If you have more supporting ideas and details to write, just continue on A4 paperusing the same format!!! 
  15. 15. SUMMARY – Organizer Handout for Chapter 5, Section 2Step 1: Read one time. * Take notes too if you want!  Reading NotesStep 2:Write the Main Idea (1-2 sentences) –______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Step 3: Write the supporting ideas. Write in the small boxes first!Step 4: Write the supporting details. Write in the bigger boxes later!Supporting Idea 1 (1-2 sentences)Supporting Details 1 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 2 (1-2 sentences)
  16. 16. Supporting Details 2 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 3 (1-2 sentences)Supporting Details 3 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 4 (1-2 sentences)Supporting Details 4 (1+ sentences)___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
  17. 17. _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 5 (1-2 sentences)Supporting Details 5 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Supporting Idea 6 (1-2 sentences)Supporting Details 6 (1+ sentences)________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________** If you have more supporting ideas and details to write, just continue on A4 paperusing the same format!!! 
  18. 18. Chemistry in a BowlPart 1 - InvestigationsMaterials:  plastic bowl (x3)  2 plastic spoons  200 mL acetic acid  50 mL of Cabbage Juice (vinegar) (x3) (x3)  2 Tbsp. sodium  1 scale (x3) bicarbonate (baking soda) (x3)Procedure 1: 1. Place 2 tbsp of baking soda into a bowl. 2. VERY CAREFULLY - Pour 50 mL or so of Cabbage Juice into the bowl. Do not let any spill out. 3. Watch carefully what happens. 4. Notice anything!?! Write below what you noticed if anything: _____________________________________________________________________________________Procedure 2: 1. Pour 2 tbsp of vinegar into another bowl. 2. VERY CAREFULLY - Pour 50 mL or so of Cabbage Juice into the bowl. Do not let any spill out. 3. Watch carefully what happens. 4. Notice anything!?! Write below what you noticed if anything: _____________________________________________________________________________________Procedure 3: 1. Place around 7 grams of baking soda into the third bowl. (Use the scale to measure) 2. Pour 100 mL of vinegar into the same bowl. 3. Notice anything!?! Write below what you noticed if anything: _____________________________________________________________________________________ 4. Wait for some time. Notice anything!?! Write below what you noticed if anything: _____________________________________________________________________________________ 5. VERY CAREFULLY - Pour 50 mL or so of Cabbage Juice into the bowl. Do not let any spill out. 6. Watch carefully what happens. 7. Notice anything!?! Write below what you noticed if anything: _____________________________________________________________________________________
  19. 19. Procedure 4 (Teacher and Student Demonstration) 1. After you have discussed what happened in the three bowls, the teacher will have a student come up and pour the all the contents of the third bowl into a bag. 2. Then, the teacher will have another student light a match for him 3. Watch while he or she holds the wooden match. 4. The other student will keep holding the bag. 5. The teacher will tell the student to open the bag as he will quickly place the burning match into the bag. 6. What do you think will happen? ______________________________.Part 2 - Observations Part 1:Fill in the chart based on what you saw or wrote in Part 1. Color? Heat Produced? Foam or Bubbles? Gas? Other? Bowl 1 Bowl 2 Bowl 3Observations - Part 2What happened when the teacher placed the match into the bag with the contents from the thirdbowl? Why? _____________________________________________________________________________________________________________________________________________________________________Part 2 - Analysis of the Investigation1) Was there a change in pH for any part of the investigations? How do you know?______________________________________________________________________________________________________________________________________________________________________________________2) What happened to the contents of the bowls? _______________________________________________________________________________________________________________________________________3) Was there ever a gas produced? How did you tell if a gas was produced?______________________________________________________________________________________________________________________________________________________________________________________
  20. 20. 4) This equation tells us what chemical reaction happened in procedure 3 when the vinegarwas added to the baking soda. Identify and count the elements on each side of the "yield" sign:NaHCO3 + HC2H3O2 -----------> NaC2H3O2 + H2O + CO2____________________________________________________________________________________________________________________________________________________________5) Place a CIRCLE around the Acid. Place a SQUARE around the Salt. Place a TRIANGLEaround the Water. Place whatever you want around the Base.6) What gas was produced in this reaction? ____________________________________________7) Was there a change in temperature? How can you tell? _______________________________________________________________________________________________________________
  21. 21. ________________________________________________ (Summary Note for Chapter 7, Section 1)As you learned earlier, there are two types of properties commonly used to describe matter (such as tapwater): physical and chemical Properties. It is also very common to consider the types of physical andchemical _______________, different types of matter will undergo in order to describe them better. Forinstance, we can recognize water easily by the fact that it is liquid at room temperature but change intoice at zero degrees. This is an example of a ____________________. However, there are also varioustypes of _________________________ that matter will undergo including things in tap water.Understanding chemical changes is really about understanding the way that the elements andmolecules that make up the matter _____________ with each other. This is the main purpose of today’sclass note.___________________________________________________? A chemical change is the changing ofthe matter itself at the atomic level. It involves a process where one or more types of matter (ie. Differentsubstances) react (usually with each other) such that the bonds between their elements get broken andnew sets of bonds are formed. As a result, when different combination of elements are formed, currentsubstance are broken down and new substances are formed. Such a process is referred to as a_________________________.For instance, if an electric current is put in water, the water molecules may react where the bondsbetween the oxygen and hydrogen atoms are broken for each molecule. And then, a new bond is madebetween the hydrogens and also a separate bond is made between the oxygens. In the process, thewater no longer “exists”. Rather the water has been changed into hydrogen and oxygen.Water (H20) --__ electricity ----- Hydrogen + Oxygen______________________________________________________- the above diagram is the typicalway for us to describe what is happening during a chemical reaction when one or more kind of matterchanges into something else. We simply list all of the participating type of matter (ie. the_______________) using their chemical formulas on one side (the left side) and then we tell what newtypes of matter (ie. the ______________________ ) the original substances become when they meeteach other and react (on the right side). As well we put an arrow in between to show the change. Such adiagram that shows describes a chemical reaction is known as a _______________________________.Reactant 1 + Reactant 2 + … etc  Product 1 + Product 2 … etc. (a chemical equation)__________________________________ – As you hopefully remember, the breaking or formation ofbonds involves the stealing (ex. ionic bonds) or sharing (ex. covalent bonds) of electrons betweendifferent elements. Some elements are very “happy” to make or break bonds because they can becomemore stable (more like the noble gases). In other words, sometimes the formation of new bonds andtherefore new types of matter is a ______________________ one. In such a case, ______________will always be _____________________ in the process because the formation of more stable bondsrequires less energy to maintain than the keeping of less stable bonds. Also the way the energy isreleased can vary depending on the specific reaction. Sometimes, heat is released. At other times, lightis released or even sound (or even some combination of all three).On the other hand, we can actually make elements bond with other elements such that they are lessstable than before. However, in such a case, we need to ___________________ to make the reactionoccur. Again, the required inputted energy form can also vary as light, sound or heat.
  22. 22. Reactant 1 + Reactant 2 + … etc +  Product 1 + Product 2 … etc. + energy (a reaction whereenergy is released)Reactant 1 + Reactant 2 + … etc + energy  Product 1 + Product 2 … etc. ( reaction whereenergy is absorved)_________________________________________The above diagrams are very general forms to describe any chemical reaction. However, when we talkabout specific reactions, we must give names to types of matter involved (ie. The types of reactants andproducts). There are different ways to do this:Method 1- _______________________________We simply use common words to describe the reactants. For example, it is known that baking soda willreact with vinegar to form carbon dioxide and a white salt. So we can describe this reaction as follows:Baking Soda + Vinegar  Carbon Dioxide + White SaltMethod 2 – Using ____________________________________You can also use specific chemical names to describe the reactants and products when writing achemical equation. (You have to just memorize them!). For example, baking soda has the chemicalname, sodium biocarbonate because it contains sodium atoms and also carbon atoms. Vinegar can alsobe called acetic acid because it contains this acid dissolved in water. The white salt that gets made isknown as sodium acetate.Sodium Bicarbonate + Acetic Acid  Carbon Dioxide + Sodium acetateMethod 3 – Using ___________________________________ – we can also use the exact formulas foreach kind of matter that specify exactly the types of elements that make them up. When using thismethod, it is also common to show exactly the number of elements involved in each reactant andproduct. To do so we must write _____________________________ to the right of elements when morethan one are involved in the formation of some substance. For instance, we know that 2 hydrogen atomsbond to one oxygen atom. So we can write this as H2O. Notice the 2 is a subscript to note the presenceof two hydrogen atoms.Second, it is also important to understand that in any reaction, substances can be broken down orformed but matter itself cannot be destroyed or created. In other words, we always end up with the samenumber of elements in the products as in the reactants. Just the atoms have combined differently withone another to make new kinds of substances. This firm rule in science is known asthe___________________________________________And as a consequence, the number of atomsin each of the reactants does not always equal the number of atoms in the corresponding products. Inturn, we may need to use ______________________________ in front of certain substances in achemical equation to ensure the law is maintained. For instance, following reaction of silver andhydrogen sulfide is not exactly proper:Ag + H2S -> Ag2S + H2Above notice, that we have more Ag atoms on the right side than on the left side. So, we have to includetwo atoms of Ag on the left side by writing a 2 cofficient next to Ag as follows. Add coeficients to ensurean equal number of atoms on both sides is referred to as balancing a chemical equation.2 Ag + H2S  Ag2S + H2
  23. 23. Now the equation above is balanced and proper.________________________- How do we actually know which elements are actually reacting withwhich elements? How can we know which bonds are breaking and which are forming. In most cases, wecannot see this directly. Instead, we have to make assumptions by _____________________________of chemical changes. Whenever, matter is changed into other forms, we can often observe differentphysical properties and then deduce what the reactants and products are. For instance, when we burnwood, we can see the solid wood change into some gas. Similarly, we can see fire being given off so wecan deduce that the reaction is exothermic where heat energy is released. In the case of vinegarreacting with baking soda, we can see bubbles being formed to deduce that one product is a gas. Wecould even collect this gas and run some other test on it (Ex. Give to plants) to show that the gas is infact carbon dioxide.
  24. 24. Balancing Equations Worksheet A. Write the correct coefficients to balance each equation below1) ____ Na3PO4 + ____ KOH  ____ NaOH + ____ K3PO42) ____ MgF2 + ____ Li2CO3  ____ MgCO3 + ____ LiF3) ____ P4 + ____ O2  ____ P2O34) ____ RbNO3 + ____ BeF2  ____ Be(NO3)2 + ____ RbF5) ____ AgNO3 + ____ Cu  ____ Cu(NO3)2 + ____ Ag6) ____ CF4 + ____ Br2  ____ CBr4 + ____ F27) ____ HCN + ____ CuSO4  ____ H2SO4 + ____ Cu(CN)28) ____ GaF3 + ____ Cs  ____ CsF + ____ Ga9) ____ BaS + ____ PtF2  ____ BaF2 + ____ PtS10) ____ N2 + ____ H2  ____ NH311) ____ NaF + ____ Br2  ____ NaBr + ____ F212) ____ Pb(OH)2 + ____ HCl  ____ H2O + ____ PbCl213) ____ AlBr3 + ____ K2SO4  ____ KBr + ____ Al2(SO4)314) ____ CH4 + ____ O2  ____ CO2 + ____ H2O15) ____ Na3PO4 + ____ CaCl2  ____ NaCl + ____ Ca3(PO4)216) ____ K + ____ Cl2  ____ KCl17) ____ Al + ____ HCl  ____ H2 + ____ AlCl318) ____ N2 + ____ F2  ____ NF319) ____ SO2 + ____ Li2Se  ____ SSe2 + ____ Li2O20) ____ NH3 + ____ H2SO4  ____ (NH4)2SO4 B. Complete the following tasks- 1. For any two equations above, find out by researching if the reaction requires energy or produces energy. 2. For any two equations above, find out the common chemical names for all reactants and products. 3. Find and describe any other chemical equation that involves water.
  25. 25. Chemical Reactions and Equations Practice – Worksheet 2Part A: Identify the following parts of each chemical formula by circling the subscripts anddrawing a square around the coefficients.H2 2 HCl 4 O2 CH4 3 CO3 2 NaOHPart B: List the symbols for the atoms in each formula and give the atom’s name ANDnumber of each. Ex. H2 --> H – two hydrogen (atoms)C2H6 2MgO 4P4O10NH3 3 Al(OH)3 2 H2O2Part C: Finish rewriting each chemical equation below by writing the full names for eachchemical formula below. (Note- you may need to look at the periodic table)Example- 2H2 + O2 _  H20  2 Hydrogen + Oxygen  Water  H + CL  HCL____________ + ______________  Hydrogen Chloride C + 2H2  CH4____________ + ______________  Methane Ag2S  2 Ag + S Silver Sulphide  ____________ ______________
  26. 26. Part D: Balance each of the following equations following the procedure described in class.Be sure to show your work.P + O2 _  P4O10 Mg + O2  _ MgOP= P= Mg = Mg =O= O= O= O=HgO  _ Hg + O2 Al2O3  _ Al + O2Hg = Hg = Al = Al =O= O= O= O= BaCl2 + H2SO4  _ BaSO4 + HCl Ba = Ba = Cl = Cl = H= H= S= S= O= O=Part E: Practice Problems –Balance each equation using the process from Part D.Cl2 + NaBr  _ NaCl + Br2 H2 + N2  _ NH3Na + Br2  _ NaBr CuCl2 + H2S  _ CuS + HClHgO + Cl2  _ HgCl + O2 C + H2  _ CH4Challenge Problem: Give it your best shot!C2H6 + O2  _ CO2 + H2O

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