Matter is constantly changing. Some changes are physical changes while others are chemical changes.

Video segment. Assistance may be required. Watch this video for a brief introduction on the physical and chemical changes in matter.

Source: Chemical and Physical Changes, Mark Drollinger, YouTube

The chart below summarizes the differences between the physical and chemical changes in matter.

Physical Change

Chemical Change
  • alters the form or appearance but does not result in the formation of a new substance
  • involves a change in size, shape, or state

Examples:

    • freezing
    • melting
    • cutting
  • results in the formation of new chemical substances
  • involves making or breaking of bonds between atoms

Examples:

    • rusting
    • burning
    • cooking

 

In a chemical change or reaction, the original substances' chemical composition is changed. You cannot get back your original substances. This would be like un-baking a cake.

Some signs (or evidence) of chemical change are

Practice

Let's see what you have learned.

Interactive exercise. Assistance may be required. Is this a physical or chemical change? Click on the correct column below.