Why Doesn’t Water Burn, Despite Being Made Of Combustible Substances (Hydrogen And Oxygen)?

Water is formed as a result of the combustion of hydrogen. In simple words, water is what you get when you burn hydrogen. So, water doesn’t burn because, in a way, it has already burned.

You get ashes when you burn paper; but when you’re burning hydrogen atoms, you get water. Just like you can’t burn ashes any further (as they’re all burnt out), you can’t burn water either!