Mole:A unit in chemistry representing Avogadro's number worth of particles (atoms, molecules, ions etc.)
Atoms/Molecules/Ions: These are basic units that make up matter; atoms form molecules and ions are charged atoms or groups of atoms.
Stoichiometry:The part of chemistry dealing with quantitative relationships between reactants and products in chemical reactions; often involves calculations using moles and Avogadroโs number.