Boiling point for many materials is very very far from the melting one; it’s much easier to add a tiny bit of energy needed to loosen the bonds between atoms/molecules, than to actually detach those atoms/molecules completely from the liquid.
If you look at a phase diagram, say for water, there’s a triple point where it can be solid, liquid, and gas at the same time. That’s at one exact temperature.
Below that pressure, it can’t be liquid at all, no matter what you do.
Above that pressure, the temperature range for the liquid phase gradually increases. So the difference between the melting and boiling points of a particular substance can be anything from zero to a lot, depending on the pressure.
And then when the pressure hits the critical point, you can’t tell the difference between liquid and gas anymore, and the whole question stops making sense.
For the same reason that you can melt water by holding it but you cant boil water by holding it. Easy to melt doesn’t mean easy to boil, its just coincidence that galliums melting point is within the range of comfortable human temps
Imagine the gallium as tiny tiny metal balls, how they interact depends on how much energy or heat is added to the balls; your hand adds this heat when you hold it. You can imagine heat as the balls vibrating, they vibrate more with more heat. When the gallium is solid there isn’t enough heat for the balls to move place each other so they form shapes called a lattice. Once enough heat is added some of the balls can start move around each other and leave the lattice, this is melting.
As the balls start to break the lattice all the heat/energy that is added is used to break the lattice, the balls don’t vibrate more, if you’re holding it in your hand you’ll notice it warms up then stays the same temperature when it starts to melt until it’s a liquid.
Once the lattice is broken it’s like taking the balls and putting them in a bin, even though they’re all solid balls they still move like water. For something to boil the balls need enough energy to fly out of the container, it takes many times more energy to fly away then it does to break the lattice
Melting is changing from a solid to a liquid and boiling is changing from a liquid to a gas. I think it seems like you think these two things have to be close together, but they don’t. Water for example, melts at 0°C and boils at 100°C, a pretty big difference though not as big as gallium. It has to do with the structure and how hard it is for heat to make the molecules move fast enough to turn into gas. Metals also boil at a higher temp in general
Often the melting point and boiling point aren’t the same for elements and compounds. I mean, think of water and ice. Ice will melt just from your body temperature (around 30c) but will boil at 100c.
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Most metals have a large gap between their melting and boiling points, Gallium isn’t unique in this
I mean water has a melting point of 0° C and boiling point of 100° C.
Same same with gallium (and other materials). Boiling ≠ Melting.
There is no set gap between melting points and boiling points. Some metals have a relatively small gap, and some have a relatively large gap. Take a look at this: http://www.sciencerockhill.com/data/melting-boiling-points-of-metals
Boiling point for many materials is very very far from the melting one; it’s much easier to add a tiny bit of energy needed to loosen the bonds between atoms/molecules, than to actually detach those atoms/molecules completely from the liquid.
Liquid phases are kind of weird.
If you look at a phase diagram, say for water, there’s a triple point where it can be solid, liquid, and gas at the same time. That’s at one exact temperature.
Below that pressure, it can’t be liquid at all, no matter what you do.
Above that pressure, the temperature range for the liquid phase gradually increases. So the difference between the melting and boiling points of a particular substance can be anything from zero to a lot, depending on the pressure.
And then when the pressure hits the critical point, you can’t tell the difference between liquid and gas anymore, and the whole question stops making sense.
This isn’t unusual. Water ice melts in your hand but has a high boiling point.
For the same reason that you can melt water by holding it but you cant boil water by holding it. Easy to melt doesn’t mean easy to boil, its just coincidence that galliums melting point is within the range of comfortable human temps
Imagine the gallium as tiny tiny metal balls, how they interact depends on how much energy or heat is added to the balls; your hand adds this heat when you hold it. You can imagine heat as the balls vibrating, they vibrate more with more heat. When the gallium is solid there isn’t enough heat for the balls to move place each other so they form shapes called a lattice. Once enough heat is added some of the balls can start move around each other and leave the lattice, this is melting.
As the balls start to break the lattice all the heat/energy that is added is used to break the lattice, the balls don’t vibrate more, if you’re holding it in your hand you’ll notice it warms up then stays the same temperature when it starts to melt until it’s a liquid.
Once the lattice is broken it’s like taking the balls and putting them in a bin, even though they’re all solid balls they still move like water. For something to boil the balls need enough energy to fly out of the container, it takes many times more energy to fly away then it does to break the lattice
Melting is changing from a solid to a liquid and boiling is changing from a liquid to a gas. I think it seems like you think these two things have to be close together, but they don’t. Water for example, melts at 0°C and boils at 100°C, a pretty big difference though not as big as gallium. It has to do with the structure and how hard it is for heat to make the molecules move fast enough to turn into gas. Metals also boil at a higher temp in general
Often the melting point and boiling point aren’t the same for elements and compounds. I mean, think of water and ice. Ice will melt just from your body temperature (around 30c) but will boil at 100c.