Atoms are made up of subatomic particles. Subatomic particles are bits of what you would have if you would take an atom apart. However, you wouldn't have anything left. Just bits.
Each atom contains: a nucleus (pictured yellow), protons (green), neutrons, and electrons. The neutrons don't have a charge. There are always an equal number of electrons and protons. Neutrons are mixed in the orbit with protons. Electrons are on an outside orbit (not pictured).
This photographic periodic table is really cool. Each element is an atom.
2 or more atoms are molecules.A compound or substance has 2 or more different elements.
All compounds are molecules, but not all molecules are compounds. So O2 (Oxygen) is a molecule only. H20 (water) is a compound.
Molecules occur in 3 forms: Solid, liquid, and gas.
Molecules have energy and are constantly in movement.
Solids are tightly packed, liquids are more loose, and gasses move around very rapidly.
We used this book for some lessons.
Wishing you homeschool blessings,