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In short - I imagine melting being the same as boiling just a hell of a lot slower.

In long - Google revealed nothing to me. I imagine that "bubbles" of liquid do form inside the solid upon reaching the melting point and even start to bubble up, but it's so slow, that they are "practically" "stable" and just link with other bubbles until the entire solid has melted.

Can you confirm that something like this happens or I'm just getting it all wrong in my head?

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Melting is the transformation from solid to liquid.

Boiling/evapiration is the transformation from liquid to gas.

If you have some kind of liquid and you heat it up enough it will boil and form bubbles of gas that rise up and escape the bulk liquid.

E.g. watch liquid nitrogen at room temperature. When you heat it from the bottom (or pour it over something at room temperature) it boils just like water.

Bubbles are just pockets of molecules (gas) that have gained enough energy to counteract all the forces inside the liquid (gravity, pressure, electrodynamic, etc) and rise up and escape.

Any liquid at any temperature will,in general, have some molecules that have enough energy to escape. This is just the idea of maxwell-boltzmann distributions. If the liquid is energetic enough then there will be enough highly energetic molecules to form bubbles

So, for example, when you melt ice you get a liquid and that liquid will have molecules of water energetic enough to escape (evaporate)--- though the cooler the liquid the less molecules like this you will have.

Usually water has gasses dissolved in it, like oxygen, nitrogen, etc. These also bubble out (e.g. open a soda and the CO2 bubbles out -though this is a pressure consideration the idea is similar)

Now for a solid like ice you can consider that the colder your sample of ice is the less and less chance you have to find localized areas of melted ice inside the ice cube; and also the lower probability that you will find a gas phase molecule anywhere in your sample.

As the temperature of your sample decreases the probability of finding a molecule in the gas phase approaches zero.

As you increase temperature the probability of finding a gas phase molecules approaches 1 (100%) as the temperature goes to infinity.

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  • $\begingroup$ What you wrote is true, but I'm not asking about boiling - I have a mental picture of that. I'm asking about melting. For example: If I take a big cube of ice and put it on a hot plate it will soon start melting. The question is - do bubbles of liquid water form inside the solid ice just like bubbles of gas form inside boiling water? $\endgroup$
    – Yordan
    Jul 2, 2016 at 19:53
  • $\begingroup$ Well i reckon that's a matter of how you define a bubble. Is a bubble something you should be able to see or is a bubble just a collections of molecules that have passed into the gas phase? $\endgroup$
    – user122066
    Jul 2, 2016 at 19:55
  • $\begingroup$ If you cpnsider the latter definition then yes, liquids contain bubbles as per maxwell-boltzmann statistics. As you melt the ice and add more enery the bubbles will get larger amd larger as more and more molecules have the speed necessary to escape. You wont see the bubbles as the ice melts because there just arent enough gas phase molecules in the ice/water $\endgroup$
    – user122066
    Jul 2, 2016 at 19:56
  • $\begingroup$ Well yes - that seems to answer my question - thank you : ) $\endgroup$
    – Yordan
    Jul 2, 2016 at 19:58
  • $\begingroup$ Bubbles could form inside the ice and this happens quite a lot. Microscopically there are localized spots in the ice that have melted and then they resolidify. There will also be loose molecules in the gas phase at the spots if it goes to the liquid phase. But they wont really be bubbles $\endgroup$
    – user122066
    Jul 2, 2016 at 19:59

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