The reaction is combination of hydrogen molecules and oxygen molecules and form water. So the oxygen and hydrogen required together is equal to the mass of the water formed.
The oxidation number<span> of a Group 2 element in a </span>compound<span> is +2. The </span>oxidation number<span> of a Group 17 element in a binary </span>compound<span> is -1. The sum of the </span>oxidation numbers<span> of all of the atoms in a neutral </span>compound<span> is 0. The sum of the </span>oxidation numbers<span> in a polyatomic ion is equal to the charge of the ion.</span>
<span>At room temperature and atmospheric pressure, nothing happens when the two gasses are mixed. However, at high temperature and pressure (450C, 200atm), in the presence of an iron oxide catalyst, the production of ammonia is thermodynamically advantageous.</span>
Comets are usually formed of ice and other suave debris, while asteroids typically contain metals.