heat
It depends on the solid but in the sun the solid will evaporate to a liquid
Liquid freezes into a solid, melts in to a liquid, then evaporate into gas and then freezes back to a liquid.
In order for a given liquid or solid to evaporate, a sufficient 'energy barrier' has to be overcome. As this barrier is different for almost all materials, the rate at which the liquid becomes a gas is most certainly different.
It is a solid that can be liquefied In order to retrieve it to the solid form you need to allow the liquid to evaporate. It will leave the solid form. It is salt when chlorine is added, creating sodium chloride.
Caffeine doesn't evaporate, it sublimes at 178 Celius, which means that it goes directly from solid to gas...not from solid to liquid to gas.
Heat is added to a solid to make a liquid... this is called melting. some additional liquid (water,ethanol,acid…) also change solid into a liquid.
Boil or evaporate it depending on the compounds involved.
The solid being added to the liquid is called a solute. When the solute is dissolved in the liquid, it forms a solution.
I think it's liquid because heating it will make it evaporate.
The liquid turns into a solid. Er, not generally. As they get hotter, most liquids tend to evaporate!
When energy is added to a solid, it can reach its melting point where it transitions from a solid to a liquid.
The name is clear: it is used to evaporate a liquid to obtain the solid residue.