Hello
Something has been bugging me ever since I learnt about superheated water in microwaves.
People keep saying that it’s because the surface is too smooth and air bubbles can’t form. But I can’t seem to find an easy to digest information about WHY smoothness prevents bubbles from forming.
I found a video explaining that heating water causes the hydrogen bonds to breaks, which makes the water molecules move about and that’s what causes bubbles. But this explanation doesn’t explain why a rugged surface is necessary in the process :/
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And I also saw that impurities in the air are necessary for water vapour to form, and that’s how clouds are formed around micro-particles from deserts. How does that work ?
Thanks 😀
In: 1
This isn’t exactly what’s happening, but it’s analogous:
Take an intact piece of printer paper. If you just grab each side in one hand and pull, you have to pull really hard before the paper will rip into two pieces, because your energy is being spread out across the entire sheet. If the paper had even a small rip on the top or bottom edge, then tearing it would be super easy because all the force gets transferred into that one spot. You don’t have to pull very hard to make the tear wider and wider until the entire page rips.
Similarly, if you have superheated water in a smooth container, the water is ready to boil, but it’s missing a trigger to set it all off. It’s easier to join an existing bubble than it is to create your own, so every water molecule is waiting for one of its buddies to be the first one to start. It’s as if the water is trying to boil across the entire surface of the container at once, and it’s like trying to pull apart a sheet of paper that doesn’t have a tear in it. The energy is being spread out evenly enough that no part reaches the tipping point. But as soon as one region gives in, the whole thing goes really fast.
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