But we do not observe any change in our container: neither today, nor tomorrow, nor in ten years. 

    Under ordinary conditions only very rare collisions result in chemical reaction. The trouble is that the hydrogen and oxygen collide as molecules. 

Before they can react they have to break up into atoms. To put it more exactly, the valence bonds between the oxygen atoms and the hydrogen atoms in their molecules must be weakened. They must be weakened to such an extent that they should not be able to prevent the combination of unlike hydrogen and oxygen atoms. 

    Now the temperature is the whip which makes the reaction go faster. It increases the number of collisions many times over. It makes the molecules vibrate more strongly, and this weakens their valence bonds. And when hydrogen and oxygen meet each other at the atomic level, they react instantly. 
 

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