Valence Bond Theory (VBT) is a chemical bonding theory that explains the formation of chemical bonds between atoms due to the overlapping of their valence orbitals. In this theory, the bond formation occurs due to the sharing of electrons between atoms, leading to the formation of covalent bonds. In this article, we will discuss the formation of H2 molecule on the basis of Valence Bond Theory.


The H2 molecule is formed by the combination of two hydrogen atoms. Each hydrogen atom has one electron in its 1s orbital. During the formation of H2 molecule, these two hydrogen atoms share their electrons to form a covalent bond.


In the H2 molecule, each hydrogen atom contributes one electron to form a covalent bond. Therefore, the H2 molecule has a total of two valence electrons.


The formation of a covalent bond between two hydrogen atoms involves the overlapping of their 1s orbitals. The two hydrogen atoms approach each other and their 1s orbitals overlap to form a molecular orbital. The molecular orbital is a combination of the two atomic orbitals.


The overlapping of the 1s orbitals of the two hydrogen atoms leads to the formation of a sigma (σ) bond. The sigma bond is formed due to the head-on overlap of the atomic orbitals. The electrons in the sigma bond are shared equally between the two hydrogen atoms.


On the basis of Valence Bond Theory, we can conclude that the H2 molecule is formed due to the sharing of valence electrons between two hydrogen atoms. The covalent bond is formed due to the overlapping of 1s orbitals of the hydrogen atoms, leading to the formation of a sigma bond.