Question

How can matter change its state?

Answer 1

Change of state can be brought about by three factors-

1)change of pressure 
2)change of temperature
3)change of both temperature and pressure

Answer 2

matter can change from one state to another if heated or cooled . If ice (a solid) is heated it changes to water (a liquid). The change is called melting.If water is heated it changes into steam (a gas)