system
Given the following post, respond as if you're commenting on Reddit:
human
If Nitrogen is so unreactive, then why is it used in explosives and fuels?

For an example, nitromethane(CH3NO2) and Hydrazine(N2H4) are both used as fuels, and when they are mixed together they produce an explosive salt. Why does this happen?
gpt
The nitrogen *molecule* (N2) is unreactive. Nitrogen compounds can be as reactive as their weakest bonds. A molecule is highly reactive if its bonds can be easily broken and recombined to a more stable molecule. When this happens, this generally liberates energy (heat in most cases). For example, when you burn methane, it combines with oxygen (a highly reactive compound) from air to form water and carbon dioxide.

CH4 + 2 O2 -> 2 H2O + CO2 + heat

Both products are very stable in normal conditions. In specific conditions, however, you may be able to turn carbon dioxide and water back into methane and oxygen, if you provide sufficient energy.

Molecular nitrogen is an extremely stable molecule and you need to spend a considerable amount of energy to break it.