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110 years ago Albert Einstein published a theory that revolutionized the way we think about the universe. In this video I'll show you how to prove its two po...

Cool Science

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Endothermic/Exothermic are the movement of heat in the environment, very much like an ice cube melt into water, water boils into vapor and vice-versa. “Endo” means absorb and “Exo” means release (like Exit or cold hearted Ex-boyfriend/girlfriend) and the most important point to remember is the direction the heat is moving - some will associate Endothermic with cold so I will explain how a ice pack works at the end :) If you put an ice cube into a stove and light the fire up, it will melt into water and then boils into steam. The ice will be absorbing the heat from the fire to make it melt then evaporate, since the direction of the heat is going in the water this process is Endothermic. Now let’s take the opposite of the ice cube melting! Vapor condensing into water then water freezing into solid ice. Think about the direction of the heat again, for the steam to cool off, the heat needs to get out somehow. Compare to popular belief, when you put a pizza in the freezer, it doesn’t absorb the cold, it lets the heat goes out so it can freeze. Let’s summarize! Melting/boiling = heat goes in = endothermic Condensing/Freezing = heat goes out = exothermic The Ice Pack Problem An Ice Pack is an endothermic reaction however it can be confusing to why absorbing heat makes the pack cold, should be the opposite. In the pack you have water and a specific kind of salt (called Ammonium Nitrate) separated by a barrier. When you crack the ice pack, the salt and water mix together. The chemical reaction absorbs almost all the heat within the water instantly forcing it to freeze. The major difference here is that the heat doesn’t go out of the pack, it’s absorbed in the water by the chemical reaction. #StayCurious

Cool Science