Bond Orbitals for Atoms Carrying Unshared Electron Pairs

BOND ORBITALS FOR ATOMS CARRYING UNSHARED ELECTRON PAIRS 

Hybridization might be expected to be quite important in ammonia, in water, and in similar compounds with unshared electron pairs because use of the 2 orbitals would make stronger bonds, perhaps of the ap type, consequently giving more stable molecules. But such hybridization does not seem to be important. The reason is that in order to use the s orbital for bond formation, an electron has to be promoted from to a higher orbital. Thus, if sp bonds 

Although changing from pure p. to. sp bonds might 

For atoms such as carbon, the js.— to p-promotion energy is compensated for by the possibility of forming more 

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