Write the electronic configuration of  ion and predict its magnetic behaviour.

Arrange the following molecular species in increasing order of stability:

Explain why H-bonding does not exist in HCl, though chlorine is quite electronegative. 

Define vander Waal's forces. 

Is hydrogen bond weaker or stronger than the vander Waal’s forces?

Why HF has higher boiling point than HCl?

Define chemical bond. Why do atoms combine (Kossel-Lewis approach) and how do atoms combine (modes of chemical combination)?

What is Lewis structure of an atom and anion?

Write Lewis symbols for the following atom and ions:
S and S^2-;  Al and Al³⁺; H and H^-.