1. Periodic Table Trends

2. Periodic Table The first periodic table was organized by Dmitri Mendeleev in 1869 The elements are organized by: –Atomic number (number of protons) –The number of valence (outer shell) electrons –Zones divided into: Metals Nonmetals Metalloids

3. Metals Solids Most have high melting points Luster (able to reflect light) Good conductors of heat Malleable (able to hammer in a flat sheet) Ductile (ability to be drawn in a wire)

4. Nonmetal Usually gas or brittle solid Only includes 17 nonmetals Includes elements that are essential for life such as oxygen and carbon

5. Metalloids Elements that share properties of metals and nonmetals. Located between the metals and nonmetals

6. Other Classificaton Groups: Also called Families Vertical columns Increase in radioactivity as you move downward Periods: Horizontal Rows Become less reactive as you move across the periods to the right.

7. Alkali Metals Group/Family 1 Has 1 valence electron Will lose 1 electron during bonding Silvery solids Low densities Highly reactive

8. Alkaline Earth Metals Group 2 Has 2 valence electrons Will lose 2 electrons when bonding Denser, harder and has a higher melting point than the Alkali metals Reactive

9. Boron Group Has 3 Valence Electrons Will give up 3 electrons when bonding All metals with the exception of Boron

10. Carbon Group Includes metals, nonmetals, and metalloids This group tends to share electrons instead of losing or gaining them. Contains 4 valence electrons

11. Nitrogen Group 5 Valence Electrons Gains 3 Electrons when bonding Includes metals, nonmetals, and metalloids Nitrogen is the most abundant element in Earth’s atmosphere.

12. Oxygen Family Includes metalloids and nonmetals 6 Valence electrons Gains 2 electrons when bonding

13. Halogens Contains 1 metalloid and 4 nonmetals 7 valence electrons Will gain 1 electron when bonding Most will form diatomic molecules (bond with themselves) Most reactive nonmetals

14. Noble Gases Most stable elements Full valence shell with 8 electrons Found only uncombined in nature Will glow when electricity passes through the noble gases