Substantially more advanced bonding theories have shown that bond strength is not always a whole number, depending on the distribution of electrons to each atom involved in a bond.
Much better illustrated than Cotton and Wilkinson and with problems, it is a better teaching aid, but it over-emphasises bonding theory in a rather daunting way.
Simple bonding theories point to the trigonal planar structure.
In contrast, the ability of the heavier noble gases to form some chemical compounds provides important insights into bonding theory.
In recent years, various human bonding theories have been developed, described in terms of attachments, ties, bonds, and affinities.
Now to know the story of how do the carbon atoms bond one must study the development of atomic theory and the different bonding theories.
Hirschi has since moved away from his bonding theory, and in co-operation with Gottfredson, developed a General Theory or "Self-Control Theory" in 1990.
Pople is widely known for his contributions to bonding theory and the development of computer programs in quantum mechanics.
In 1704, Isaac Newton famously outlined his atomic bonding theory, in "Query 31" of his Opticks, whereby atoms attach to each other by some "force".
As Mülhaupt aptly notes, this is due in part to the fact that molecular structure and bonding theory were not fully understood in the early 20th century.