eli5: why does potassium react so violently with water but is harmless to us in let’s say a banana ?
In: 7
It’s a matter of potential energy.
Pure potassium has a lot of potential energy. When you oxidize it (for example by dropping it in water) that potential energy gets converted to light and heat. But now it’s already combined. That’s the state it’s in in a banana so you can’t get additional energy out of it.
Imagine a bowling ball on a pendulum that has been pulled back. That has a lot of potential energy. If you let go that energy is released, and if your face is in the way it will hurt. But once the ball stops swinging it’s already released the energy (possibly because it was transferred into someone’s face). You can give that bowling ball a big smooch and, aside from all your friends thinking you’re a weirdo, no harm would come.
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