Estimate the order of magnitude of actual energy of covalent reaction

Answer ::

In acovalent bond, atoms share electrons. This reduces the quantum confinement energy of the electrons because the electron wavefunctions spread out over the two atoms. A bond between two identical atoms is always a covalent bond. While electrostatic force also play a role in covalent bond, the most important energy is the quantum confinement energy.

To estimate the strength of a covalent bond, a three-dimensional square well can be used as a simple model for an atom. The lowest energy of an electron in a three-dimensional square well is,

E= 3h² / 8mL^2.

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