Molecules
A molecule consists of two or more atoms that bond by sharing their outer electrons.
Oxygen gas (O2)
and water (H20) are examples of molecules.
Compound = a chemical
substance that is formed from two or more elements, that bond in a fixed ratio.
For example, water (H2O) is a compound that is composed of two
hydrogen atoms for every oxygen atom. A compound is a pure substance.
Covalent Bonding is where 2 or more atoms bond by sharing their outer electrons. Generally, covalent bonds are made between nonmetal atoms. The result of this bond is a molecule. Covalent means, "Sharing outer electrons".