system
Given the following post, respond as if you're commenting on Reddit:
human
With nothing but hydrogen and oxygen, how come water isn't flammable?

It sounds like the ingredients of a bomb!
gpt
For the same reason CO2 isn't, and the same reason an anvil on the ground can't fall on your head.  Water is what you get when hydrogen is burnt.  It's already ashes.  You can't burn ashes.

Scientifically: Water is at a very low energy state.  For a chemical reaction to release energy, it has to move from a high energy to a low energy state.  Many explosive compounds have lots of nitrogens hanging off at unhappy angles.  Nitrogen likes to form a sturdy triple bond with itself, so when its hanging off a chemical its like stretching a rubber band- a lot of energy is stored.  When the nitrogen is liberated, it snaps together with another nitrogen atom and all the energy gets turned into velocity and jiggling, aka pressure and heat.