This seemed like an easy question, but the more I think about it, the more stumped I am. What’s the difference between liquid and gas? I realize that the simple answer is “heat”, but why?
Let’s take water. I get that when it is cold, it sticks together, and forms something that appears to be rigid. Fine. Heat that up, and it breaks apart, and suddenly the molecules can all roll around independently as a liquid. Still fine. Apply more heat and now…what? They’re still in basically the same state, it seems. How come all of a sudden, they float up into the air and no longer dissolve salt and fish can’t breathe it and so on?
Steam and liquid water seem like they should be more or less the same to me, molecules that are not sticking together. Educate me as to why that isn’t the case.