The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. It can only be transformed from one form to another.

Here's a breakdown:

* Chemical reactions involve the rearrangement of atoms and molecules.

* Atoms are the fundamental building blocks of matter. They cannot be created or destroyed in a chemical reaction.

* Mass is a fundamental property of matter. Since atoms are not created or destroyed, the total mass of the reactants (starting materials) must equal the total mass of the products (substances formed).

Example:

When you burn wood, it appears to disappear. However, the wood has been transformed into ashes, smoke, and gases. The total mass of the ashes, smoke, and gases will equal the original mass of the wood.

In summary: The Law of Conservation of Mass is a fundamental principle in chemistry and physics, stating that matter cannot be created or destroyed in a chemical reaction.