Exothermic vs Endothermic Changes and a Note About Heat
let's examine exothermic and endothermic reactions* a bit more thoroughly! *for the purpose of thermochemistry, i'll refer to all changes in matter as "reactions" exothermic - heat energy is released into the surroundings (i.e. "produces heat") the products of exothermic reactions have less potential energy than the reactants examples: freezing - liquid water forming ice at 0 degC ⇌ energy + condensation - water vapour turns into water droplets ⇌ energy + it might seem a bit unintuitive to think of these reactions as producing "heat" but it makes sense if you think about it! the three states of matter... classic molecules in a liquid have more kinetic ("heat") energy than a solid - they're free to slip and slide around as they please! liquid molecules - full of energy and a little like a bouncy ball pit! in a solid, they just sit near each other and vibrate solid molecules - not very...