Breaking chemical bonds is typically an endothermic process, which means energy must be added (it must pull in energy)
Breaking of chemical bonds is always endothermic meaning it wants energy, so it takes energy from its surroundings and sucks it in. Think of 'endo' as inside. The chemical bonds want energy inside of it so it can break.
Forming of chemical bonds is exothermic, meaning it releases energy into its surroundings. Think of 'exo' as outside, or exterior, it releases its energy outside of itself.
I hope that makes some kind of sense :)
Make a cylinder which will be the glass and put a piece of paper that appears to be the top waterline of water. And put that inside the glass. I am not sure if this made any sense but yep thats what i did for a project before when i had to in like fourth grade.
sunlight would be the answer to your question
