Here's the breakdown:

* Atoms: The fundamental building blocks of matter. They are the smallest unit of an element that retains the chemical properties of that element.

* Molecules: Two or more atoms held together by chemical bonds. These bonds are formed by the sharing or transfer of electrons between atoms.

Examples:

* Water (H₂O): Two hydrogen atoms bonded to one oxygen atom.

* Carbon dioxide (CO₂): One carbon atom bonded to two oxygen atoms.

* Glucose (C₆H₁₂O₆): Six carbon atoms, twelve hydrogen atoms, and six oxygen atoms bonded together.

Key Points:

* Molecules can be made up of the same type of atom (like oxygen gas, O₂) or different types of atoms (like water, H₂O).

* The arrangement and bonding of atoms within a molecule determine its properties and behavior.

* Molecules are essential for life and make up everything around us, from the air we breathe to the food we eat.