H2 Gas: Stability and Reactivity on Earth's Surface

[Simfish]

If it didn't escape to space so easily, then would it easily react with other things on Earth's surface?

 

[Borek]

Yes.

 

[enigma]

Hydrogen gas + oxygen gas = boom

See rockets for examples. They usually use liquid h2, but its the same principle

 

[Nemus]

You need about 2% hydrogen in air to form an explosive mixture but it would probably be relatively short lived in the atmosphere. Compare with methane for example. I have a vague recollection that it has a half life of some decades in the atmosphere.