Burning fuels such as hydrocarbons is useful because it releases light and what kind of energy?

Hydrocarbon fuels like methane (CH4) burn in the presence of oxygen to produce carbon dioxide and water. This process of combustion releases energy. When energy is released during the course of a chemical reaction, it is said to be an EXOTHERMIC reaction.

Explanation:

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.