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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Bond length

The distance between the nuclei of two bonded atoms, at the minimum of the potential-energy curve. For the same two atoms, a higher bond order gives a shorter bond.

Potential energy of two H atomsEnergy of two hydrogen atoms against the distance between their nuclei. Far apart the energy is zero; it falls to a minimum of −436 kJ/mol at 74 pm (the bond length; the depth is the bond energy) and rises steeply when the nuclei are pushed closer.74150225300−4360400distance between nuclei (pm)energy (kJ/mol)bond lengthbond energy

The bond length is the distance at the bottom of the energy well.

Example

C–C 154 pm, C=C 134 pm, C≡C 120 pm. In OX3\ce{O3} both O–O bonds are 128 pm (bond order 1.5), between HX2OX2\ce{H2O2} (148 pm) and OX2\ce{O2} (121 pm).

See alsoBond energyBond orderMultiple bondResonance hybrid