A Molecule is the smallest component of a compound which exhibits the chemical properties of the compound. In molecules the individual atoms are bonded together by covalent bonds. These molecules are overall electrically neutral although they can have a dipole. These internal bonds are strong and hard to break.

The molecules of a compound are bound together into solids and liquids by Van der Waals forces which are very weak. Other forces also can help and the reason that water (a molecule lighter than carbon dioxide) is a liquid at room temperature is because it has a strong dipole and the bonds between the water molecules have a very strong ionic character. In fact ice is much more ionic than molecular in character.

There are other forms of material that are not molecular but are also not elemental in nature.

  • ionic materials are composed of charged ions which are held together by electrostatic forces.
  • metallic solids are composed of atoms which are very tightly bound by covalent style bonds. However the electrons are not isolated in individual bonds as the orbitals extend through the material. While some metals are elemental most are alloys of some form.