Introduction
Chemical changes
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances.
Here is an example of a chemical change:

Frying an egg is a chemical change because the liquid component of the egg changes from liquid to solid.
Here is a video explaining more:
https://www.youtube.com/watch?v=x49BtB5dOwg
(you will have to copy and paste the link into a new tab)
In a chemical change, the atoms in the reactants rearrange themselves and bond together differently to form one or more new products with different characteristics than the reactants. When a new substance is formed, the change is called a chemical change. During a chemical reaction, no atoms are created or destroyed. The atoms are rearranged. This results in the formation of new substances with different properties to the starting substances.