There are two H2 .There are four nitrogen atoms present. There are two NH3 formed
1.) When a man is engaged to continuous exercise or work, not only his muscles are working but also there is increase in the rate of respiration too. This accelerated rate of respiration and heartbeat provides more oxygen and food to the body. So all the organs and organ systems work in coordination.
2.) I'm sorry that I don't know the answer to your question. The one which I know, I have already written.
Beryllium because it's a metal which is in nature usually found as cations held together by delocalized electrons and there is also a trend on the periodic table which suggests that ionization energy increases from left to right across a period and decreases from top to bottom down a group