mass doesn't change
solid
it is a solid
the matter can change into liquid, solid and gas.
Heating can change matter from a solid to a liquid or from a liquid to a gas. Cooling can change matter from a gas to a liquid or from a liquid to a solid.
Solid state of matter is characterized by resistance to a change in volume or shape.
Physical change
When something changes between solid, liquid, gas, or plasma
This change in the state of matter (liquid to solid) is called freezing; it is a physical change, the chemical nature of the molecules is not changed.
state of matter
Ice is the solid state of matter for water. Being a solid is a physical property, not a change.
If you add heat to matter, it can either get it hotter, or it can change the state of matter (for example, from solid to liquid).
freezing