Who proposed Valence Bond Theory? Explain the formation of N 2 molecule by using this theory.

In 1931 Valence bond theory was proposed by Linus Pauling and John C. Slater. According to valence bond theory, the number of bonds formed by an atom is equal to the number of unpaired electrons present in it. Also, only those two atoms make a bond that has an unpaired electron with an opposite spin. Formation of N 2 molecules by valence bond theory : The electronic configuration of ‘ N ’ atom is 2, 5 and to have Octet in the valence shell requires three more electrons. When two nitrogen atoms approach each other, each atom contributes 3 electrons for bonding. There are six electrons shared between two nitrogen atoms in the form of three pairs.