Why is a single bond the longest bond?

Question

Ava Andrews · Accepted Answer

It comes down to the number of shared electrons that create the electron density between the two nuclei. The greater the amount of charge in the region between the nuclei, the shorter the bond.

Single, double, and triple bonds—such as the C to C bond in organic compounds—between the same two elements should be taken into account when comparing apples to apples. A double bond involves twice as many electrons as a single bond, which forms when one pair of electrons is shared by the two atoms. The more electrons that are spending time between the two atoms' nuclei, the more force these electrons exert on the nuclei and the closer the nuclei are drawn together before attractions and repulsions balance in a stable bond. This is improved even further by a triple bond, which has three pairs of bonding electrons occupying the space between the nuclei.

Isabella Acosta · Answer

undefined A single bond is the longest bond because it consists of the weakest type of bond, a sigma bond, which allows for more distance between the nuclei of the bonded atoms compared to double or triple bonds.