The structure of sodium azide (NaN3) is represented as [N=N=N]^- Na^+, indicating its ionic nature and crystal structure. The discussion highlights the challenge in determining the bonding in NaN3 using valence bond or molecular orbital theory. Nitrogen exists as a diatomic gas (N2) due to its molecular structure, while phosphorus is a solid, attributed to stronger van der Waals forces resulting from its larger molecular size. The conversation also touches on the types of intermolecular forces present, confirming that van der Waals forces play a significant role in the physical states of nitrogen and phosphorus. Overall, the differences in molecular structure and intermolecular forces explain the contrasting states of these elements at standard temperature and pressure.