1. Catalyst: Begin working on the handout at the front. Make sure you look up the definition of Lewis Dot Diagrams!

3. Groups or Families The physical and chemical properties of elements repeat in a predictable way when atomic numbers are used, this is called periodic law. Comparison of Groups (Families) SimilaritiesDifferences Chemical propertiesTotal number of electrons Number of valence electronsAtomic mass ChargeReactivity

4. Classes of Elements Three ways to classify the elements: 1.Solids, liquids, and gases based on state at room temp 2.Those that occur naturally and those that do not 3.Metals, nonmetals, or metalloids (based off of general properties) Metal Nonmetal Metalloid

6. Metals Properties Good conductors of electricity and heat Solids at room temp (except for mercury) Most are malleable (can be shaped) Palladium Mercury

7. Metals Many are ductile (can be drawn into thin wires) Some are very reactive Some do not react easily Sodium and Water Lithium and Water

8. Nonmetals Poor conductors of heat and electricity Low boiling points Many are gases at room temp

9. Nonmetals Solid nonmetals at room temp are brittle Broad range of reactivity Sulfur

10. Metalloids Properties fall between metals and nonmetals Ability to conduct electricity varies with temp Silicon Germanium

11. Group 1: Alkali Metals Single valence electron (+1) Contains Li, Na, K, Rb, Cs, Fr Like to give away e- Very reactive Found in nature only as compounds EXAMPLE: Table Salt (Na + Cl)

12. Group 2: Alkaline Earth Metals Two valence electrons (+2) Contains Be, Mg, Ca, Sr, Ba, Ra Like to give away e- Harder than group 1 Reactivity is temp dependent Important for biological functions Calcium important for bones Magnesium plays key role in photosynthesis of green leafy plants

13. Group 3: Boron Family Three valence electrons (+3) Contains metalloid Boron and Al, Ga, In, Tl Contains Aluminum- most abundant metal in Earth’s crust Aluminum used for many things Gutters Window Frames Airplanes

14. Group 4: Carbon Family Four valence electrons (+4) Group contains nonmetal (C), two metalloids (Si/Ge), & two metals (Sn/Pb) Metallic nature increases from top to bottom Except for H 2 O, most of the compounds in body contain Carbon Silicon in form of SiO 2 Silicon carbide on saw blades makes longer lasting

15. Group 7: Halogens 7 valence electrons Highly reactive nonmetals Contains F, Cl, Br, I, At Though physically different they’re very similar chemically Chlorine used to kill bacteria in pools Fluoride in toothpaste to prevent tooth decay Seafood is a good source of iodine

16. Group 8: The Noble Gases Outer shell of electron cloud is full 8 valence electrons except for He (2) Colorless and odorless Extremely unreactive Used in “neon” lights