What Is Valence Bond Theory ?

Definition of Valence Bond Theory
Valence Bond Theory
Explaining the nature of the chemical bond in a molecule of the atomic valence angle.

The central atom in a molecule tends to form a double electron bonds corresponding geometric constraints specified by the octet rule.

History of Valence Bond Theory
Lewis-Kossel-Langmuir 
theory of valence electrons
Bohr
Asking the electron configurations call as K, L, M, and N shell.
Werner Heisenberg dan  Erwin Schrodinger
Modified by development in Quantum Mechanics by Bohr
Fritz London dan Walter Heitler
Application of the first quantum mechanics to the chemical system and the hydrogen molecule.

Basic Postulates of Valence Bond Theory
  • Valence bond occurs because of the attractive force on unpaired electrons in the atom.
  • Electron-electron pairs have opposite spin direction.
  • The electrons that have been paired again can not form bonds with other electrons.
  • The combination of electrons in bonding can only be represented by a wave equation for each atom.
  • The electrons in the lowest energy level will make the couple ties the most powerful.
  • Two orbitals of an atom, orbital with the ability to multiply which will form the strongest bond and tend to be at it orbital concentrate.
Application of Valence Bond Theory

A. Application of Valence Bond Theory In A Diatomic Molecule

Valence bond theory assumes that a chemical bond forms when two valence electrons to work and keep the two atomic nuclear together.

Therefore, the effect of decreasing the energy system, this theory applies well on a diatomic molecule.

According to this theory, the electrons in a molecule occupy atomic orbitals of each atom. Application of valence bond theory in diatomic molecules can be seen in the formation of H₂.

B. Application of Valence Bond Theory In Polyatomic Molecules

Valence bond theory can also be applied in conjunction with the polyatomic molecule molecular hybridization theory.

In this example is presented the application of valence bond theory to explain the SP3 hybridization in molecules of methane (CH₄).

*Sumber: Poppy Dwita, Hardian Wahyu Perdana, Kevin Septioga, Sodaya Ummi
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