Malay, when I answered your first question, it was before this thread was moved to the homework help area. In this area, we are requested not to give out answers, but to help you to find the answer yourself. What steps have you taken to find an answer, and what progress have you made?
1)I was not able to find the bonding in NaN3 either by VB theory or by MO theory, but I guessed that it should be ionic and hence should have crystal structure.
2)I studied about existence of nitrogen molecules and phosphorus molecules but could not deduce anything relevant to the question.
What kind of intermolecular forces exist between Nitrogen and Phosphorous? Is it Van Der Waal? Permanent Dipoles? Ionic?
Well, i'll answer that... It's van der waal foces....
but what is the difference between these two molecules? of how much atoms does nitrogen consists and of how much atoms does phosphorous consist in one molecule?
If phosphorous exists in solid state, therefore, its van der waal forces should be stronger... what causes this? what increases the van der waal forces?