Here's a breakdown:

* Atoms are the fundamental building blocks of matter. They are incredibly small and consist of a nucleus (protons and neutrons) surrounded by electrons.

* Molecules are formed when two or more atoms bond together chemically. This bond involves the sharing or transfer of electrons between the atoms.

There are many different types of molecules, with varying numbers and types of atoms. Some examples include:

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

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

* Sugar (C₁₂H₂₂O₁₁): Twelve carbon atoms, twenty-two hydrogen atoms, and eleven oxygen atoms bonded together

So, whenever you see something made up of more than one atom, it's likely a molecule!