Here's why:
* Molecule: A molecule is the smallest unit of a compound that retains the chemical properties of that compound. A water molecule is made up of two hydrogen atoms (H) bonded to one oxygen atom (O).
* Atoms: Atoms are the fundamental building blocks of all matter. They are smaller than molecules.
* Subatomic particles: Atoms are made up of even smaller particles called protons, neutrons, and electrons.
So, while a water molecule can be broken down into its constituent atoms (hydrogen and oxygen), it is the smallest unit that still exhibits the properties of water (like being a liquid at room temperature, dissolving many substances, etc.).
