What is Melting and Freezing?

Our world is made of matter.
The earth's crust is solid, the sea is liquid, and the air is a mixture of gases. Some matter, such as rocks and wood, are called solids.
They don't change their shape.
Lemonade and water are called liquids because they flow easily. If you pour a liquid into a container, it flows to fill up the shape of the container. The surface of the liquid is always level.
Gases, like the air we breathe, spread to fill any space.
Substances remain as solids, liquids, or gases at certain temperatures. If they are heated or cooled, they change.
If you pour water into a container and leave it in the freezer of a refrigerator, the liquid water changes into a solid, ice. If you heat water until it boils, the liquid water becomes a gas.
If you put some liquid water into the freezer, it soon turns into ice. When you take the ice out of the freezer, it melts back to liquid water again. Ice is solid water.
Freezing water to make ice does not change the water into a different substance — it just changes the form of the water.
Water changes to ice when the temperature falls below 32 °F (0 °C).
Ice melts when the temperature rises above 32 °F (0 °C).
This temperature is called the freezing point of water and the melting point of ice.