Why doesn't methane react with oxygen t room tempurature?

Answer 1

This is a molecular chemistry question.

The methane and the oxygen need to have sufficient amount of heat (random kinetic energy) to overcome the energy barrier preventing them from reacting. If the collisions between them are not hard enough, they won't react.

It is kind of like a hill that they have to get over, and room temperature is just to low to give them enough energy to get over the top.

But once they start reacting, the reaction generates so much heat (random kinetic energy) that the other methane and oxygen molecules around them begin to react.