Chemical changes involve the rearrangement of atoms to form new substances with different properties. Here's a breakdown:

* Atoms: The fundamental building blocks of matter. They cannot be created or destroyed in chemical reactions.

* Chemical Change: A process where the chemical composition of a substance changes. This involves breaking existing chemical bonds between atoms and forming new ones.

* New Substances: The rearrangement of atoms results in the formation of substances with different properties than the original substances.

Example:

Imagine burning wood. Wood is made of complex molecules containing carbon, hydrogen, and oxygen. When you burn it, the heat provides energy to break these bonds and rearrange the atoms to form new substances: carbon dioxide (CO2) and water (H2O). The wood is gone, and we have new substances with different properties (gas vs. solid).

Let me know if you have any other questions about chemical changes!