1. Bonds, Atomic Bonds

2. Valence Number  Number of electrons an atom has in its outer energy level.  All atoms want 8 electrons in their outer energy level.  A happy and stable atom has 8 electrons in its outer energy level. 8

3. Oxidation Number  Number of electrons an atom will gain, lose, or share while bonding with another element.

4. Group Number Group NameValence Number Oxidation Number 1Alkali Metals1+1 2Alkaline Earth Metals 2+2 3 -12Transitional Elements 1 or 2---- 13Boron family3+3 14Carbon family4+4 or -4 15Nitrogen family5-3 16Oxygen family6-2 17Halogens7 18Noble Gases80

5. 3 Types of Chemical Bonds 1.Ionic Bonds 2.Covalent Bonds 3.Metallic Bonds

6. Ions Recall that p + have charge +1, e - have charge -1 –# p + = # e - : no net charge = neutral –# p + > # e - : net + charge = Cation –# p + < # e - : net - charge = Anion

7. Ionic compounds Crystal lattice – strong forces High melting and boiling points Hard, not easily crushed Conduct when melted or dissolved

8. Covalent compounds Weaker forces between compounds Lower melting and boiling points Volatile liquids and gases Softer – easily crushed Not conductors

9. Ionic Charged particles carry current Lit bulb Covalent No charged particles Unlit bulb

10. Properties of metals Luster Conductors Malleable Ductile

11. Lewis Dot Diagram: Elements Shows the number of electrons in the outer energy level of an atom –“valence electrons”

12. Electron Dot Diagram Symbol surrounded by dots to represent the valence electrons

13. LEWIS’ DOT FORMULAS Represent The Outer Shell Only Never More Than 8 Electrons Used To Show How And Why Elements Combine With Each Other