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
Be ause starting to form a bubble or rain drop takes a lot of energy. The rugged surface or the air impurity gets the process started to get to a point where it takes less energy for the bubble or rain drop to form.
Imagine a small bubble trying to form. It’s a sphere, but it’s so small that the surface tension around it outside is very high because of how tight it has to curve around the bubble. This potential energy needs to be collected before the bubble can form, so ots very unlikely to happen on its own. If it does happen, it’s much easier for the bubble to shrink and dissappear than it is for the bubble to grow to a stable size. Once the bubble reaches a certain size, it actually takes less energy to grow than it does to shrink, so at that point, it’s stable. What the rugged surface does is it offers the gas a place where it doesn’t need to create as much surface tension to form a bubble, so it can get past that small, unstable phase faster and with less energy.
It’s the same idea with rain drops. Literally the same concept.
Also, it doesn’t need it to form vapor, just droplets. Droplets are just an aeroslized liquid, vapor is just a gas.
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