Polyatomic
Describe a molecule with two or more atoms
Particle
Composed of either a single, unbound atom or a molecule
Atom
The building blocks from which all matter is made of
Monatomic
A single, unbound atom
Pure substance
A substance composed of only one kind of particle
Diatomic
A molecule with exactly two atoms
Element
A substance composed of only one kind of atom
Molecule
any two or more atoms bonded together
Compound
Two or more different atoms bounded together
Mixture
A substance composed of two or more particles