Well,
An element is a collection of atoms (isotopes) that have the same number of protons.
Molecules are multiple atoms that bond together to form a new substance with its own unique properties.
A chemical bond is a bond between atoms that holds the atoms together to make the molecule.
A compound is a mixture of molecules that have different chemical properties.
A mixture is a mixture (redundancy) of molecules.
A substance is basically a thing, such as a particle, atom, compound, mixture, or molecule.
