Ionic and Covalent Bonds

Most recent answer: 10/22/2007

Q:
In school right now we are learning pre-chemistry and, I would like know a little bit more about ionic and covalent bonds, and how you can tell between both of these when you are writing a formula for a compound.
- Mateo Forero (age 12)
The Altamont School, Birmingham AL (U.S)
A:
Covalent bonds, like the bonds between the oxygens in O2, leave the same charge concentration on each side. The energy of the elctrons in the bond is lowered because they can spread out compared to in the non-bonded atoms. The reason why that spreading lowers the energy is not understandable without a little quantum mechanics.
Ionic bonds have one (or more) electrons moved from the vicinity of one atom to the vicinity of another. The remaining charged oppositely charged ions then attract. The reasons that the electrons would move in the first place are also purely quantum mechanical.

Most bonds, except between identical atoms, are part covalent and part ionic.

Mike W

(published on 10/22/2007)