Part of Pauling's work on the nature of the chemical bond led to his introduction of the concept of orbital hybridization. While it is normal to think of the electrons in an atom as being described by orbitals of types such as s and p, it turns out that in describing the bonding in molecules, it is better to construct functions that partake of some of the properties of each. Thus the one 2s and three 2p orbitals in a carbon atom can be (mathematically) 'mixed' or combined to make four equivalent orbitals (called sp3 hybrid orbitals), which would be the appropriate orbitals to describe carbon compounds such as methane, or the 2s orbital may be combined with two of the 2p orbitals to make three equivalent orbitals (called sp hybrid orbitals), with the remaining 2p orbital unhybridized, which would be the appropriate orbitals to describe certain unsaturated carbon compounds such as ethylene. Other hybridization schemes are also found in other types of molecules. Another area which he explored was the relationship between ionic bonding, where electrons are transferred between atoms, and covalent bonding, where electrons are shared between atoms on an equal basis. Pauling showed that these were merely extremes, and that for most actual cases of bonding, the quantum-mechanical wave function for a polar molecule AB is a combination of wave functions for covalent and ionic molecules. Here Pauling's electronegativity concept is particularly useful; the electronegativity difference between a pair of atoms will be the surest predictor of the degree of ionicity of the bond.
part of pauling's work on the nature of the chemical bond led to his introduction of the concept of orbital hybridization while it is normal to think of the electrons in an atom as being described by orbitals of types such as s and p it turns out that in describing the bonding in molecules it is better to construct functions that partake of some of the properties of each thus the one 2s and three 2p orbitals in a carbon atom can be (mathematically) 'mixed' or combined to make four equivalent orbitals (called sp3 hybrid orbitals) which would be the appropriate orbitals to describe carbon compounds such as methane or the 2s orbital may be combined with two of the 2p orbitals to make three equivalent orbitals (called sp hybrid orbitals) with the remaining 2p orbital unhybridized which would be the appropriate orbitals to describe certain unsaturated carbon compounds such as ethylene other hybridization schemes are also found in other types of molecules another area which he explored was the relationship between ionic bonding where electrons are transferred between atoms and covalent bonding where electrons are shared between atoms on an equal basis pauling showed that these were merely extremes and that for most actual cases of bonding the quantum-mechanical wave function for a polar molecule ab is a combination of wave functions for covalent and ionic molecules here pauling's electronegativity concept is particularly useful; the electronegativity difference between a pair of atoms will be the surest predictor of the degree of ionicity of the bond