Mystery #1Tier 2-3chemistry / energy
Why do some reactions get hot, and others get cold?
Mix two things together and sometimes the bowl turns warm in your hands. Mix two others and the bowl goes cold, cold enough to mist up. Nothing was heated and nothing was put in a fridge. So where does the heat suddenly come from, and where does it go?
Your guess
What's your hunch about why mixing chemicals would make something hotter OR colder all by itself?
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