Periodic Table Electron configurations Charges (stable ions for compounds) Trends (size, ionization energy, electronegativity) Polarity of bonds (greater difference in electronegativity, more polar) Determine formulas of compounds (Ionic and Non-ionic)

Clicker #1 Rank the following bonds from least polar to most polar: Si-Cl P-ClMg-ClS-Cl A) S-Cl, P-Cl, Mg-Cl, Si-Cl B) P-Cl, S-Cl, Si-Cl, Mg-Cl C) Mg-Cl, Si-Cl, P-Cl, S-Cl D) Mg-Cl, S-Cl, P-Cl, Si-Cl E) S-Cl, P-Cl, Si-Cl, Mg-Cl

Localized Electron Model (LEM) Increase probability that we know where electrons are We assume electrons are always where we place them

Localized Electron Model (LEM) Increase probability that we know where electrons are We assume electrons are always where we place them FORMULASHAPESPROPERTIES OF MOLECULES H20H20

Localized Electron Model (LEM) Increase probability that we know where electrons are We assume electrons are always where we place them Electrons shared in order to lower energy state of molecule (“fill shell”) FORMULASHAPESPROPERTIES OF MOLECULES H20H20

Localized Electron Model (LEM) LEM = LEWIS STRUCTURES!! Assume ONLY the valence electrons matter I.e. - N : 1s 2 2s 2 2p 3

Localized Electron Model (LEM) LEM = LEWIS STRUCTURES!! Assume ONLY the valence electrons matter I.e. - N : 1s 2 2s 2 2p 3 5 valence electrons

Clicker #2 How many electrons would hydrogen have to share in a covalent bond in order to have a noble gas electron configuration? A) 0 B) 2 C) 3 D) 6 E) 8

Clicker #3 How many valence electrons are in NO 3 – ? A) 4 B) 18 C) 23 D) 24 E) 32