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The bond dissociation energy (enthalpy) [4] is also referred to as bond disruption energy, bond energy, bond strength, or binding energy (abbreviation: BDE, BE, or D). It is defined as the standard enthalpy change of the following fission: R—X → R + X. The BDE, denoted by Dº(R—X), is usually derived by the thermochemical equation,
Bond energy and bond-dissociation energy are measures of the binding energy between the atoms in a chemical bond. It is the energy required to disassemble a molecule into its constituent atoms. This energy appears as chemical energy, such as that released in chemical explosions, the burning of chemical fuel and biological processes. Bond ...
The term bond-dissociation energy is similar to the related notion of bond-dissociation enthalpy (or bond enthalpy), which is sometimes used interchangeably.However, some authors make the distinction that the bond-dissociation energy (D 0) refers to the enthalpy change at 0 K, while the term bond-dissociation enthalpy is used for the enthalpy change at 298 K (unambiguously denoted DH° 298).
Finally the reaction enthalpy may be estimated using bond energies for the bonds which are broken and formed in the reaction of interest. This method is only approximate, however, because a reported bond energy is only an average value for different molecules with bonds between the same elements. [12]
IE Li, the first ionization energy of gaseous lithium. B(F–F), the standard enthalpy of atomization (or bond energy) of fluorine gas. EA F, the electron affinity of a fluorine atom. U L, the lattice energy of lithium fluoride. The sum of these enthalpies give the standard enthalpy of formation (Δ f H) of lithium fluoride:
The following table lists some binding energies and mass defect values. [21] Notice also that we use 1 Da = 931.494 028 (23) MeV/c 2. To calculate the binding energy we use the formula Z (m p + m e) + N m n − m nuclide where Z denotes the number of protons in the nuclides and N their number of neutrons.
Enthalpy of atomization is the amount of enthalpy change when bonds of the compound are broken and the component atoms are separated into single atoms ( or monoatom). Enthalpy of atomization is denoted by the symbol ΔH at. The enthalpy change of atomization of gaseous H 2 O is, for example, the sum of the HO–H and H–OH bond dissociation ...
The energy E i is the ionization energy corresponding to the chosen atomic orbital and U is the energy shift of the orbital as a result of the potential of neighboring atoms. The n ± 1 | H | n = − Δ {\displaystyle \langle n\pm 1|H|n\rangle =-\Delta } elements, which are the Slater and Koster interatomic matrix elements , are the bond ...