Glossary of Frequently Used Bonding Terms?

  • Primary Bonds = Chemical (strong) Bonding
    i.e., ionic, covalent or metallic bonds.

  • Secondary Bonds = Physical (weak) Bonding
    i.e., hydrogen and van der Waals bonds.

  • Directional Bonds = Multiple bonds that
    are localized and occur at fixed angles with
    respect to each other.

  • Covalent Bonds = The attainment of
    the "magical octet" of outer electrons by
    atoms sharing pairs of valence electrons.

    - Each shared pair constitutes a single bond
    - Covalent bonds are directional

  • Ionic Bonds = The establishment of the "Noble
    Gas Configuration" by electron transfer from metallic
    atoms to non-metallic atoms.

    - The electro-static bond is thus formed between
      positively charged metallic ions (cations) and
      negatively charged non-metallic ions (anions).

  • Metallic Bonds = The bonds formed between an
    array of positively charged metallic cations and a "sea"
    of negatively charged electrons, the latter being donated
    from the outer shells of the constituent atoms.

    - Metallic bonds are non-directional.

  • Hydrogen Bonds = Weak, secondary bonds
    formed by the attraction of polar molecules.

    - A polar molecule (or dipole) results from a
      permanent imbalance in the electron distribution
      in a molecule, e.g., between an electro-negative
      atom (oxygen)and an electro-positive atom (hydrogen).

  • Van der Waals Bonds = Weak, secondary bonds formed
    by the attraction of fluctuating dipoles between atoms of
    the noble gases.

    - Van der Waals bonds are non-directional.