Problem+Set+11

Solutions to Problem Set 11 1. (Drawings left out) a) [Xe] 6s^1 One Valence Electron

b) 1s^2 2s^2 2p^6 3s^2 3p^2 Four Valence Electrons

c) 1s^2 2s^2 2p^6 3s^2 3p^5 7 Valence Electrons

d) [Ar] 4s^1 One Valence Electron

e) [Ar]4s^13d^10 One Valence Electron

f) [Ar] 4s^2 3d^10 4p^5 7 Valence Electrons

g) [Kr] 5s^2 5p^6 5d^10 Eight Valence Electrons

(Ethan M.)

2. Valance electrons increase across periods excluding transition and inner transition metals. (Natalie)

3. a. Ca - lose 2 b. Li - lose 1 c. S - gain 2 d. Cu - lose 1 e. I - gain 1 (Natalie)

5. A 2-D particle diagram of sodium chloride with electric field lines is as follows; (Marielle Billig)

6. NaCl is electrically neutral, because Na+ and Cl- interact to form formula units, in which the positive Na+ charge and negative Cl- charge "equalize" each other in the compound with a neutral charge. (Alex Kaplan)

8. notes: each time "becomes" signifies atoms gaining or losing electrons to become ions. also, in formula units numbers should be subscript. a. Ca & I _ Ca becomes Ca^2+, I becomes I^- _ formula unit: CaI2 b. Li & 0 _____ Li becomes Li^+, O becomes O^2- _ formula unit: Li2O c. Cu & Cl _ __Cu becomes Cu^+, Cl becomes Cl^-__ __formula unit: CuCl__ __d. Ag & F__ __Ag becomes Ag^+, F becomes F^-__ _ _ formula unit: AgF e. U & O _ U becomes U^3+, O becomes O^2- __ _ formula unit: U2O3

9. It's incorrect to refer to NaCl as a molecule because when an ionic bond is formed, the compound arranges itself in a lattice structure, not in individual and isolatable molecules. You can't break down the lattice structure into molecules, because the ions are bonded to many things around them, not just the other things in their formula. We call NaCl (and all other compounds that are ionic) a formula unit because it tells us the ratio of sodium to chloride, and we can only call covalently bonded compounds molecules. (Kevin Ray)