[toadesque]

I have solid NH3 (ammonia)

It's asking for the

a. Type of Crystal

b. Major intermolecular forces

c. Type of Particles

d. Two properties

My prof. didn't have time to explain this before the final and I'm not getting much help from my book. Based on what I know, the type of crystal should be either molecular solid, atomic solid, or ionic solid right? If so how do I determine which one it is?

[toadesque]

Also I have to outline this unit cell and write the formula.

http://img132.imageshack.us/img132/3148/eweedc5.jpg

would it be repeating if i plced an X under all the A's and a B under all the C's? I'm sorry if I sound stupid by saying that but this was yet another topic that the prof didn't explain to us and I'm trying to figure this out on my own.