Decribe how hydrogen and oxygen form water

Well, its a very simple process actually. Here is how it works;

When molecular hydrogen, also known as H2, and oxygen, also known as O2, are combined and are able to react together, energy is released and the molecules of the hydrogen and the oxygen. These can combine to form either water or hydrogen peroxide, depending on how the chemicals mix.

I hope I made your day a little easier,

Have a great day and happy Halloween!