A solid can turn into a liquid if you put heat. For example, if you put blocks of ice in a pot and you put that pot on a stove, the solid will turn into a liquid. That is called melting.A liquid can turn into a solid. For example, if you try to make popsicles, you need to put water and juice in the freezer. The liquid will freeze and turn into a solid. That is call freezing. Liquids can turn into gases. For example, if you are trying to make soup, like stone soup, the water will turn into a gas if you boil it. That is call evaporation. Also gas can turn into a liquid. For example a pot if that pot is with water and you put heat and you open the pot many gas will turn into water and it will be out the pot that is called condensation as how you can see temperatures change matter.