This is properly called "freezing". Occasionally, it can be called "solidifying", but that's not really correct.
Yes.
it causes all to under go a phase change. solids change into liquids by melting, liquids turn into gas by evaporation and......well, i have no freakin idea how gas changes actually
solid and liquid
Solids become liquids. A phase change.
Solids
Gases
Covalent compounds can be solids, liquids or gases.
changes from one state to another without a change in chemical composition
Light travels in the air phase of matter compared to the liquids and solids.
In general matter expands its temperature and volume with heat.This heat energy causes an increase of energy internal to the matter that expands its volume: solids melt to liquids, liquids expand to gases; and gases transform to plasma. At phase temperatures the matter changes form with no change in temperature;
A solution is a homogeneous mixture of two or more liquids, only one phase. When another phase exist (for example solids, immiscible liquids) this is not a true solution.
They are all something in something else. Suspensions are colloids. Colloids are something small dispersed in something else - solids in liquids (a suspension), gases in liquids, gases in solids etc etc Solutions are one phase - a liquid, but at least 2 compounds make up that phase.