Change happens every day! Sometimes we notice the change, such as the water on the pond turning to ice. Sometimes we do not notice change, such as blood changing colour within the lungs when carbon dioxide and oxygen are exchanged. In this activity, you will learn the difference between physical and chemical changes.

Two types of changes occur around us: physical changes and chemical changes.

A physical change rearranges molecules, but it doesn't affect their internal structures.

For example, when you step on a can and crush it, you have forced a physical change. However, you only changed the shape of the can. It wasn't a change in the state of matter because the energy in the can did not change. Also, since this was a physical change, the molecules in the can are still the same molecules. No chemical bonds were created or broken.

@gettyimages

         

In a physical change, a material changes from one state to another with the ability to change back into its original state. The composition of the material remains the same in all states.

The states of all matter are solid, liquid, and gas. For example, water can go from a solid to a liquid to a gas and then back to a liquid and back to a solid. We see these changes every year as water evaporates into a gas, comes down as rain, and then freezes into ice in the winter.

A chemical change, on the other hand, occurs when two or more materials react and create new materials. The new materials have completely different properties from the original materials. For example, baking a cake.

@creativecommons