The concept of hybridization is a useful model to explain the shape, bond angles and Lewis structure of molecules. It was developed by Linus Pauling in 1932, the same year that he introduced the idea of electronegativity. I first came across it at university and it has a somewhat chequered history in pre-university syllabuses. During the 1970s and 1980s it appeared on British A level syllabuses but it has subsequently...