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.

However, exothermic reactions don't always release heat, sometimes the energy is released as light. For example, glowsticks release light without increasing in temperature. 2. The beaker now ...

The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration. The combustion of methane is an example of an exothermic reaction. More energy is released when ...