The question is incomplete but i will try to give you all the necessary guide that you need in order to answer the question.
When compounds are formed, atoms exchange valency. The valency of nitrogen is three while that of the metal is two. The exchange yields M3N2.
If the compound has been specifically mentioned to be a metal, then it must be a group two element. It could be any of Mg, Ca, Sr, Ba or Ra. I did not mention Be here because most of its compounds are covalent.
This will help you to answer the complete question.
Because the cohesive forces inside the droplets are stronger than the adhesive forces between both the drops and the wax, water does not penetrate waxed surfaces. Because the adhesive forces between the liquid and the glass are stronger than the cohesive forces inside the water, water wets glass and spreads out across it.
