Do NowExplain in detail how you arrange yourclothes at home.How are products arranged and stacked on shelvesin a grocery store?
How is the periodictable used toclassify and provideinformation about allknown elements?
Using the Periodic Table • How are elements arranged on the periodic table? • What can you learn about elements from the periodic table?
How does sorting help scientists understandWhat they are studying?Sorting helps scientists understand how thingsare similar and how they are differentExplain in your own words what you think theperiodic table is?
What is the periodic table?• The periodic table is a chart of the elements arranged into rows and columns according to their physical and chemical properties.• It can be used to determine the relationships among the elements.
100 table The periodic table is a chart of the elements arranged into rows and columns according to their physical and chemical properties.
Developing a Periodic Table• In 1869 Dimitri Mendeleev was working on a way to classify elements.• At the time, more than 60 elements had been discovered.
Developing a Periodic Table Russian chemist and Periodic table of the Teacher who lived in elements; a system for the 1800s organizing the elements
Developing a Periodic Table• Mendeleev studied the physical properties such as density, color, melting point and atomic mass of each element.• He also noted chemical properties such as how each element reacted with other elements.• Mendeleev arranged the elements in a list using their atomic mass.
Mendeleev’s Periodic Table
density ColorMelting and boiling point atomic mass
Mendeleev noticed in his table that meltingpoint is one property that shows a repeatingpattern.
Problems with Mendeleev’s Table• Mendeleev’s periodic table enabled scientists to relate the properties of the known elements to their position on the table• However, the table had a problem!! Some elements seemed out of place.
Henry Moseley• In the early 1900’s, the scientist Henry Moseley solved the problem with the periodic table.• Moseley listed the elements according to increasing ATOMIC NUMBER
When Moseley listed the elementsaccording to atomic number, columnscontained elements with similar properties,such as copper, silver, and gold.
propertiesAtomic mass Atomic Number patterns
Developing a Periodic Table (cont.) What determines where an element is located on the periodic table you use today?
Today’s Periodic TableYou can identify many of the properties of anelement from its placement on the periodictable. period Science Use the completion of a cycle; a row on the periodic table Common Use a point used to mark the end of a sentence; a time frame
The table is organized into columns, rows, andblocks, which are based on certain patterns ofproperties.
Today’s Periodic Table (cont.)• The element key shows an element’s chemical symbol, atomic number, and atomic mass.• The key also contains a symbol that shows the state of matter at room temperature.
Today’s Periodic Table (cont.)• A group is a column on the periodic table.• Elements in the same group have similar chemical properties and react with other elements in similar ways.
Today’s Periodic Table (cont.) What can you infer about the properties of two elements in the same group?
Today’s Periodic Table (cont.)• The rows on the periodic table are called periods.• The atomic number of each element increases by one as you read from left to right across each period.
Today’s Periodic Table (cont.)• Metals are on the left side and in the middle of the periodic table.• With the exception of hydrogen, nonmetals are located on the right side of the periodic table.• Between the metals and the nonmetals on the periodic table are the metalloids.
How Scientists Use the PeriodicTableEven today, new elements are created inlaboratories, named, and added to thepresent-day periodic table.
How Scientists Use the PeriodicTable (cont.)• Scientists can use the periodic table to predict the properties of new elements they create.• The periodic table contains more than 100 elements, each with its unique properties that differ from the properties of other elements.
• On the periodic table, elements are arranged according to increasing atomic numbers and similar properties.
• A column of the periodic table is called a group. Elements in the same group have similar properties.
• A row of the periodic table is called a period. Properties of elements repeat in the same pattern from left to right across each period.
How did Mendeleev arrangeelements when he first used atable to classify elements?A. columns of increasing atomic massB. rows of increasing atomic massC. rows of increasing atomic numberD. rows of decreasing atomic number
What does the element key of aperiodic table indicate?A. chemical symbolB. atomic numberC. atomic massD. all of these
Where are all nonmetals (with theexception of hydrogen) locatedon the periodic table?A. top halfB. right sideC. left sideD. bottom half
Do you agree or disagree?1. The elements on the periodic table are arranged in rows in the order they were discovered.2. The properties of an element are related to the element’s location on the periodic table.
Metals• What elements are metals?• What are the properties of metals?
What is a metal?• More than three-quarters of the elements on the periodic table are metals.• With the exception of hydrogen, all of the elements in groups 1-12 on the periodic table are metals.• Some of the elements in groups 13-15 are metals.
What is a metal? (cont.)To be a metal, an element must havecertain properties. How does the position of an element on the periodic table allow you to determine if the element is a metal?
What is a metal? (cont.)• A metal is an element that is generally shiny. It is easily pulled into wires or hammered into thin sheets. A metal is a good conductor of electricity and thermal energy.• Luster describes the ability of a metal to reflect light.
What is a metal? (cont.)Ductility is the ability to be pulled intothin wires. ductility from Latin ductilis, means “may be led or drawn”
What is a metal? (cont.)• Malleability is the ability of a substance to be hammered or rolled into sheets.• Gold is so malleable that it can be hammered into thin sheets.• In general the density, strength, boiling point, and melting point of a metal are greater than those of other elements.
What is a metal? (cont.) What are some physical properties of metals?
Group 1: Alkali Metals• The elements in group 1 are called alkali metals.• The alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium.• Alkali metals react quickly with other elements, such as oxygen and in nature, occur only in compounds.
Group 1: Alkali Metals (cont.)Alkali metals react violently with water.They are also soft enough to be cut witha knife.
Group 2: Alkaline Earth Metals• The elements in group 2 on the periodic table are called alkaline earth metals.• The alkaline earth metals are beryllium, magnesium, calcium, strontium, barium, and radium.
Group 2: Alkaline Earth Metals (cont.)Pure alkaline earth metals do not occurnaturally but instead combine with otherelements and form compounds.
Groups 3-12: Transition ElementsThe elements in groups 3-12 are calledtransition elements.
Groups 3-12: Transition Elements (cont.)• Transition elements are in a block at the center and two rows at the bottom of the periodic table.• Many colorful materials contain small amounts of transition elements.
Groups 3-12: Transition Elements (cont.)• All transition elements are metals with higher melting points, greater strength, and higher densities than the alkali metals and the alkaline earth metals.• Because of their high densities, strength, and resistance to corrosion, transition elements make good building materials.
Groups 3-12: Transition Elements (cont.)Two rows of transition elements—thelanthanide and actinide series—were removedfrom the main part of the table so that periods6 and 7 were not longer than the other periods.
Patterns in Properties of MetalsMetallic properties include luster,malleability, and electrical conductivity.
• Properties of metals include conductivity, luster, malleability, and ductility.
• Alkali metals and alkaline earth metals react easily with other elements. These metals make up groups 1 and 2 on the periodic table.
• Transition elements make up groups 3-12 and the lanthanide and actinide series on the periodic table.
Which term describes the abilityof a metal to reflect light?A. malleabilityB. ductilityC. lusterD. alkaline
Which of the following is true ofalkaline earth metals?A. They all belong to the same period.B. They react quickly with other elements.C. They include gold.D. All of the above are true.
Which of the following distinguishestransition elements from alkali metals?A. Transition elements have higher melting points.B. Transition elements have greater strength.C. Transition elements have higher densities.D. All of the above are true.
Do you agree or disagree?3. Fewer than half of the elements are metals.4. Metals are usually good conductors of electricity.
Nonmetals and Metalloids • Where are nonmetals and metalloids on the periodic table? • What are the properties of nonmetals and metalloids?
Nonmetals and Metalloids • nonmetal • halogen • noble gas • metalloid • semiconductor
The Elements of LifeMore than 96 percentof the mass of thehuman body comesfrom four nonmetals–oxygen, carbon,hydrogen, andnitrogen.
The Elements of Life (cont.)• Nonmetals are elements that have no metallic properties.• The four elements that make up most of the human body, along with phosphorus and sulfur, are the six elements in proteins, fats, nucleic acids, and other large molecules in your body and in all other living things.
How are nonmetals different frommetals?• Nonmetals have properties that are different from those of metals.• Many nonmetals are gases at room temperature and those that are solid at room temperature have a dull surface, which means they have no luster.• Because nonmetals are poor conductors of electricity and thermal energy, they are good insulators.
Phosphorus and carbon are dull, brittlesolids that do not conduct thermal energyor electricity.
How are nonmetals different frommetals? (cont.) What properties do nonmetals have?
How are nonmetals different frommetals? (cont.)An element in group 17 of the periodictable is galled a halogen. halogen from Greek hals, means “salt”; and –gen, means “to produce”
How are nonmetals different frommetals? (cont.)The term halogen refers to an element thatcan react with a metal and form a salt.
How are nonmetals different frommetals? (cont.)• Halogens react readily with other elements and form compounds.• Halogens can only occur naturally in compounds.• In general, halogens are less reactive as you move down the group.
How are nonmetals different frommetals? (cont.)The elements in group 18 are known asthe noble gases.
How are nonmetals different frommetals? (cont.)• Unlike the halogens, the only way elements in this group react with other elements is under special conditions in a laboratory.• Of all the elements, hydrogen has the smallest atomic mass and is the most common element in the universe.
How are nonmetals different frommetals? (cont.)• Hydrogen is most often classified as a nonmetal because it has many properties like those of nonmetals.• However, hydrogen also has some properties similar to those of the group 1 alkali metals.• Under conditions on Earth, hydrogen usually behaves as a nonmetal.
Between the metals and the nonmetalson the periodic table are elements knownas metalloids.
Metalloids (cont.)• A metalloid is an element that has physical and chemical properties of both metals and nonmetals.• The elements boron, silicon, germanium, arsenic, antimony, tellurium, polonium, and astatine are metalloids.• Silicon is the most abundant metalloid in the universe.
Metalloids (cont.) Where are metalloids on the periodic table?
Metalloids (cont.)• A property of metalloids is the ability to act as a semiconductor.• A semiconductor conducts electricity at high temperatures, but not at low temperatures.
Metalloids (cont.)Silicon is used in making semiconductordevices for computers and other electronicproducts. semiconductor from Latin semi-, means “half”; and conducere, means “to bring together”
Metals, Nonmetals, andMetalloids• An element’s position on the periodic table tells you a lot about the element.• Understanding the properties of elements can help you decide which element to use in a given situation.
• A nonmetal is an element that has no metallic properties. Solid nonmetals are dull and brittle and do not conduct thermal energy or electricity.
• Halogens and noble gases are nonmetals. These elements are found in group 17 and group 18 of the periodic table.
• Metalloids have some metallic properties and some nonmetallic properties. The most important use of metalloids is as semiconductors.
What term refers to elements ingroup 18 that only react with otherelements under special laboratoryconditions?A. halogenB. nonmetalsC. noble gasesD. metalloid
Which term refers to an element thatconducts electricity at hightemperatures, but not at lowtemperatures?A. metalB. conductorC. halogenD. semiconductor
Which term refers to an elementthat can react with a metal andform a salt?A. halogenB. noble gasC. semiconductorD. none of the above
Do you agree or disagree?5. Most of the elements in living things are nonmetals.6. Even though they look very different, oxygen and sulfur share some similar properties.
Key Concept SummaryInteractive Concept MapChapter ReviewStandardized Test Practice
Elements aregrouped andorganized on theperiodic tableaccording toincreasing atomicnumber and similarproperties.
Lesson 1: Using the Periodic Table• Elements are organized on the periodic table by increasing atomic number and similar properties.• Elements in the same group, or column, of the periodic table have similar properties.• Elements’ properties change across a period, which is a row of the periodic table.• Each element key on the periodic table provides the name, symbol, atomic number, and atomic mass for an element.
Lesson 2: Metals• Metals are located on the left and middle parts of the periodic table.• Metals are elements that have ductility, malleability, luster, and conductivity.• The alkali metals are in group 1 of the periodic table, and the alkaline earth metals are in group 2.• Transition elements are metals in groups 3-12 of the periodic table, as well as the lanthanide and actinide series.
Lesson 3: Nonmetals and Metalloids• Nonmetals are on the right side of the periodic table, and metalloids are located between metals and nonmetals.• Nonmetals are elements that have no metallic properties. Solid nonmetals are dull in appearance, brittle, and do not conduct electricity. Metalloids are elements that have properties of both metals and nonmetals.• Some metalloids are semiconductors.• Elements in group 17 are called halogens, and elements in group 18 are noble gases.
Can new elements created inlaboratories be added to theperiodic table?A. noB. yesC. Maybe, but it has never been done.D. none of these
What is another name for acolumn on the periodic table?A. groupB. rowC. periodD. block
Which term refers to a metal’sability to be pulled into thinwires?A. lusterB. ductilityC. malleabilityD. alkali
What term refers to elements thathave no metallic properties?A. metalloidsB. metalsC. nonmetalsD. semiconductors
More than 96 percent of the mass ofthe human body comes from fournonmetals—oxygen, carbon,hydrogen, and what else?A. boronB. siliconC. nitrogenD. none of these
Where are metals found on theperiodic table?A. topB. left side and in the middleC. right sideD. bottom
Which group of metals includessodium, potassium, and cesium?A. alkali metalsB. alkaline earth metalsC. transitional elementsD. nonmetals
Which term refers to the ability ofa substance to be hammered orrolled into sheets?A. lusterB. ductilityC. malleabilityD. conductivity
Of all the elements, which onehas the smallest atomic mass?A. carbonB. sulfurC. hydrogenD. nitrogen
Metallic properties of theelements tend to do what as youmove down a group?A. increaseB. decreaseC. remain the sameD. none of these