In this video, I explain why some reactions explode while others cool, exploring the root cause of chemical energy. I discuss the chemistry behind endothermic and exothermic reactions, which involves ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

American Journal of Science, October.—On endothermic reactions effected by mechanical force, by M. Carey Lea. The object of this investigation was to find whether the blackening effects of pressure ...

Speaker one Have you ever had a bump or a sprain and needed a cold compress? Speaker two Yes, all the time. Now, some cold packs use a chemical reaction to absorb heat. This is an example of something ...