https://doi.org/10.1351/goldbook.B00701
The average value of the gas-phase @B00699@ (usually at a temperature of \(298\ \text{K}\)) for all @B00697@ of the same type within the same @CT01038@. The mean bond energy for methane, for example, is one-fourth the @E02141@ of reaction for:
B00701.png
Tabulated bond energies are generally values of bond energies averaged over a number of selected typical chemical species containing that type of bond.
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1090 [Terms] [Paper]