MATTERS AND ITS PROPERTIES 4

Unir: What changes of matter are there?. There are two types of changes in matter: physical changes and chemical changes. Chemical changes are irreversible. Physical changes are reversible. A reversible change is when something can return to its original form. An irreversible change is when something can't return to its original form.

Unir: Sarah is cooking pancakes. The mixture changes from liquid to solid. This is an irreversible change. When the pancakes cool, they don't become liquid again. Chemical changes are irreversible.

Unir: Physical changes are reversible. Daniel is heating chocolate. The chocolate changes from solid to liquid. This is a reversible change. When the liquid chocolate cools, it becomes solid again.

Unir: Physical changes. Chemical changes.