Valence Electrons

Electrons on the outer shell (valence shell) (ex. Be has 2, Cl has 7)

Examples

Bohr models of Na, Cl, identify # of valence e-

Lewis-Dot Diagrams

Lewis-Dot diagrams of Na, Cl (see below)

Octet Rule

All atoms want a valence shell with eight electrons

Examples

Na (has an extra, wants to give one),  Cl (green marker, needs one more, wants to take one)

Cations and Anions

Na⁺ (show Lewis Diagram w/one valence e-), Cl^- (show Lewis w/seven valence e-)

-Na⁺ = cation (positive)                  Cl^- = anion (negative)