11) How many lone pairs of electrons are on the S atom in SF4 ?

A) 0

B) 1

C) 2

D) 3

12) How many lone pairs are on the Br atom in BrCl2-?

A) 0

B) 1

C) 2

D) 3

13) In the best Lewis structure for NO +, what is the formal charge on the N atom?

A) -1

B) 0

C) +1

D) +2

4.3   Short Answer Questions

1) Among the compounds H3C–CH3, H2C=CH2, and HCCH, the compound with the strongest carbon-carbon bond is ________, and the compound with the longest carbon-carbon bond is ________.

2) Ionic compounds consist of a single three-dimensional network of ions that are attracted to one another by strong ________ and usually exist in the solid state at room temperature, whereas covalent compounds consist of molecules that are attracted to one another by weak ________ and can exist in gaseous, liquid, or solid state at room temperature.

3) Of the bonds C–C, C–N, C–O, and C–F, the bond that is most polar is ________.

4) The Lewis electron-dot structure of N2 has ________ nonbonding electrons pairs, ________ bonding electron pairs, and a bond order of ________.

5) The Lewis electron-dot structure of H2CO has ________ nonbonding electron pairs, ________ bonding electron pairs, and a carbon-oxygen bond order of ________.

6) The number of Lewis electron dot resonance structures required to describe NO2– is ________.

7) Based on formal charges, the best Lewis electron-dot structure of BF3 has a B–F bond order = ________.