CHEMISTRY DOTS!

i need help on doin dot diagrams. where do the dots go?

1. a) C2H4

b) PBR3

c) OCl2

d) SiCl4

e) H3COH

f) BH3

g) H2S


2. Explain why Ccl4 dissolves in O2 but not in H2O. Draw all dot diagrams, show dipoles, angle, and polarity.


3. Draw the dot diagram for the following molecules, draw the dipoles and indicate the polarity of the molecule.

a) CS2

b) CF4

c) HCN

d) NH3

e) H2S

f) H3CPH2


Please help me and explanation would be nice.