Melting

Key Stage 2

Melting is when a solid turns into a liquid.

Verb: To melt

When you heat a solid:

A solid will melt and become a liquid.

Most solids can be melted to become a liquid.

Melting is a reversible process. When a solid melts you can always freeze it back into a solid.

You may have seen these solids melt


Some ice cubes melt to make water.	Wax melts because of the flame.

Chocolate can melt in your mouth because your mouth is warm.	You can melt butter in a frying pan.

Melting is an endothermic process in which a solid turns into a liquid.

Most solids can be melted to become a liquid.

Melting is a reversible process. When a solid melts you can always freeze it back into a solid.

A solid can be melted by heating it.

When you heat a solid:

The particles in the solid vibrate faster until they vibrate fast enough that they break the bonds holding them in fixed positions. The particles become able to move past each other but are still touching which makes the state a liquid.

Melting happens when the particles in a solid break bonds holding them in fixed positions as they gain potential energy.

The temperature at which a substance melts is called its melting point.

Melting is an endothermic process, which means it needs to absorb energy to take place.

Melting is a physical change, which means it is reversible and does not produce new chemicals.


As a solid is heated the internal energy increases. As the solid melts the temperature of the substance stays the same but the potential energy of the particles continues to increase.