Strength+of+covalent+bonds

The strength of a covalent bond is determined by the amount of energy required to break it. The strength of a bond also relates to the stability of the molecule in which it resides. Perhaps the most common relation regarding bond strength is the length of bonds. The more electrons an atom shares with another, the shorter the distance between the two atoms.
 * Strength of Covalent Bonds**

As you can see, the atoms are closer when more electron pairs are shared. If a molecule contained a triple bond, sharing six electrons, then the atoms would be even closer, resulting in stronger bonds. The table below shows the average bond lengths and strengths for single, double, and triple bonds between two carbon atoms:

kJ/mol-1 || Bond length nm ||
 * Bond || Bond strength
 * C-C || 348 || 0.154 ||
 * C=C || 612 || 0.134 ||
 * C__=__C || 837 || 0.120 ||

There is a simple reason for this. As the negatively charged electrons congregate between the two atoms, they are attracted to each of the positively charged nuclei, and the nuclei are attracted to the electrons. The more electrons that are present, the stronger the attraction between the opposite charges, and the closer the atoms become. If the attraction is stronger, it is harder to break, thus creating stronger, shorter covalent bonds.

Brown, LeMay, Bursten. __Chemistry: the Central Science__. Pearson Education: Upper Saddle River, 2003.
 * So****urces:**
 * [|ibchem.com/IB/ibnotes/full/bon_htm/4.2.htm]**