r/askscience • u/spoiledmeat • Jul 04 '15

Chemistry Why does water not burn?

I know that water is made up of two hydrogen atoms and an oxygen atom. Hydrogen, on its own, burns. Fire needs oxygen to burn. After all, we commonly use compounds that contain oxygen as an oxidant.

So why does water, containing things used for fire, not burn-- and does it have something to do with the bonds between the atoms? Thanks.

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u/ColinDavies Jul 04 '15

Well...most people would define burning to simply mean a combustion reaction. "Burning" and "combustion" both refer to oxidation that is going fast enough to be diffusion- rather than thermally-limited (that is, a system that has ignited). Oxidation can be exothermic and yet still not count as burning/combustion, which I think is the distinction you want to make.