What happens to the fuel when a rocket takes off.

When a rocket takes off liquid oxygen and

liquid hydrogen mix (than ignited) it makes a water molecule. As that happens heaps of energy is released. This energy heats the water to become VERY hot, as it is so hot its evaporation and lists of the rocket up.

Most people believe that the cloud coming from the below the rocket (as seen in picture on right) is smoke. Mostly the cloud of smoke is actually water clouds. That’s why whenever a rocket takes off it always rains.