[str33t punk]

hey guys I was thinking to myself today.. I thought that oxygen is flameble.. hydrogen is also flameble then why isn't water (H2O= hydrogen2 Oxegen)
flameble?

[Unknown008]

Because, it is another chemical with different properties. Only a mixture will retain its original properties.

[AndMadMan]

Hydrogen and Oxygen could be considered to be high energy molecules. You can actually mix hydrogen and oxygen without a reaction. Once you provide the activation energy, typically a spark or other catalyst, the molecules react releasing energy. Water is a low energy molecule compared to hydrogen and oxygen.

[str33t punk]

So when both of the molecules mix they accually an stay flammable if they don't have a reaction but once they do it turns into a molecule with lower energy?

[robkelly2242]

It is really frightening how little you people know about basic chemistry. Or spelling. Or grammar. But you know a lot of buzzwords.

[Unknown008]

When these molecules (O2 and H2) react to form water, they lose their energy as heat and light in common cases. Therefore it is obvious that water will have less energy.

The opposite happens to reactions involving absorption of energy, where the resultant products have more energy than the reactants themselves.

For example, heating water, causes it to absorb water, thus gaining enough energy to be converted into a gas, which is steam.

[templelane]

I'm surprised no one has mentioned electrons and orbitals yet.

Oxygen is a reactive species because it required an additional two electrons to fill it's outer shell and become stable.

Hydrogen is also a reactive species because it requires the loss of an outer electron to become stable.

When two hydrogens react with one oxygen they share their outer electrons with the oxygen to complete it's outer shell. This produces a stable molecule which has no need to proceed in further reactions i.e. it is not reactive or flammable. It is energetically stable http://homepages.ius.edu/GKIRCHNE/Water6.jpg

[Unknown008]

Water is not VERY reactive you mean, because there are reactions involving water. Anyway, water is not flammable and that instead of burning, water absorbs the heat given to it to change state.

[templelane]

Good point Unknown I did oversimplify.

[Unknown008]

Never mind. :D That often happens.