My chemistry teacher once explained it to me like below. Does anyone know how much truth there is to this explanation?
Temperature as measured by a thermometer or your finger is an average. Not every single molecule has the same temperature. The molecules constantly bounce around, smashing into each other, transferring heat to each other. By chance, some molecules will get hit in just the right way by other molecules to reach a very high temperature and then it evaporates. So there is constantly a gradient of temperatures among the molecules and the ones with the highest temperature are the ones evaporating, until there is no liquid left at all.
As the average temperature increases, the chance of some molecules reaching a high enough temperature also increases, so warm water evaporates faster than cold water.
This also explains why evaporation cools down (like when you sweat): the molecules with the highest temperature are the ones evaporating, so the average temperature decreases as those high-temperature molecules leave the system. Only the relatively colder molecules are left behind - thus it cools as a whole.
There’s a bit more to it, but it’s because of this effect.
There is actually a balance between liquid and gas state, just overwhelmingly in favor of liquid when at normal temperatures. There is a ratio of molecules that will hit each other and transition to gas, and an equal amount gas hitting liquid and condensing. At least when there is a balance between the two sides, aka 100% moisture in the air. Which is not how it is most places.
Normally there is always evaporated water in the air, and anything that evaporated will be moved away in any mildy ventilated area, as you say, it leaves the system. So it never reaches a balance, which is why things dry up at lower temps as water will always evaporate and leave the system.
I think it’s much easier and truthful to stop talking about temperature and introduce speed in that context.
The average speed is what we percieve as temperature, but single molecules can be fast, so fast as to break the boundaries of the liquid pool and shoot up toward space.
But temperature is not just the speed of a molecule right? Isn’t it also like the “energy” stored in the molecule, or its “wiggling” or something? Like a molecule moving very fast through space can still be at a very low temperature, right?
But temperature is not just the speed of a molecule right?
It pretty much is.
Like a molecule moving very fast through space can still be at a very low temperature, right?
That very much depends on the relative speed of the molecule and you. If you’re not moving in relation to the molecule, a collision between you and it won’t do much. Now try being hit by it (or a bunch of them) at high or even relativistic speeds. The area of you that’s hit will surely become pretty hot then.
Like, have you seen footage of asteroid impacts? Have you seen shooting stars? Those are hot. Like, non-figuratively.
It’s kinetic energy, temperature itself is not a real thing, you are dealing with the bonds that keep water molecules together, if you wiggle hard enought, with enough energy (so… fast enough?) you break free.
I guess another way to look at it is the cloud of elecrons getting more and more messy, so that it destabilizes the bonds…
My chemistry teacher once explained it to me like below. Does anyone know how much truth there is to this explanation?
Temperature as measured by a thermometer or your finger is an average. Not every single molecule has the same temperature. The molecules constantly bounce around, smashing into each other, transferring heat to each other. By chance, some molecules will get hit in just the right way by other molecules to reach a very high temperature and then it evaporates. So there is constantly a gradient of temperatures among the molecules and the ones with the highest temperature are the ones evaporating, until there is no liquid left at all.
As the average temperature increases, the chance of some molecules reaching a high enough temperature also increases, so warm water evaporates faster than cold water.
This also explains why evaporation cools down (like when you sweat): the molecules with the highest temperature are the ones evaporating, so the average temperature decreases as those high-temperature molecules leave the system. Only the relatively colder molecules are left behind - thus it cools as a whole.
There’s a bit more to it, but it’s because of this effect.
There is actually a balance between liquid and gas state, just overwhelmingly in favor of liquid when at normal temperatures. There is a ratio of molecules that will hit each other and transition to gas, and an equal amount gas hitting liquid and condensing. At least when there is a balance between the two sides, aka 100% moisture in the air. Which is not how it is most places.
Normally there is always evaporated water in the air, and anything that evaporated will be moved away in any mildy ventilated area, as you say, it leaves the system. So it never reaches a balance, which is why things dry up at lower temps as water will always evaporate and leave the system.
I think it’s much easier and truthful to stop talking about temperature and introduce speed in that context.
The average speed is what we percieve as temperature, but single molecules can be fast, so fast as to break the boundaries of the liquid pool and shoot up toward space.
Single unbounded molecules are what gas is.
But temperature is not just the speed of a molecule right? Isn’t it also like the “energy” stored in the molecule, or its “wiggling” or something? Like a molecule moving very fast through space can still be at a very low temperature, right?
It pretty much is.
That very much depends on the relative speed of the molecule and you. If you’re not moving in relation to the molecule, a collision between you and it won’t do much. Now try being hit by it (or a bunch of them) at high or even relativistic speeds. The area of you that’s hit will surely become pretty hot then.
Like, have you seen footage of asteroid impacts? Have you seen shooting stars? Those are hot. Like, non-figuratively.
Wait it’s all models? Alwasy has been.
It’s kinetic energy, temperature itself is not a real thing, you are dealing with the bonds that keep water molecules together, if you wiggle hard enought, with enough energy (so… fast enough?) you break free.
I guess another way to look at it is the cloud of elecrons getting more and more messy, so that it destabilizes the bonds…