Iron oxide, aluminum, and a catalyst ... in an exothermic reaction. The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration. The combustion of methane is ...

The reaction shown by the second diagram is more exothermic. There is a greater difference in energy between the reactants and products. The green arrow is longer.

Catalysts are useful because they do not get used up during a reaction. Exothermic and endothermic reactions Exothermic reactions release energy into the surroundings, so they usually feel hot.