1 Fundamental ideas behind the chemical bond
Simple theories of chemical bonding are based on the idea of the electron-pair bond, and the extent to which a pair of valence electrons is shared between the atoms that are bonded together.
Note – the key word here is extent – you’ll see why this is later.
In addition there is also an assumption that the electronic structures of noble gas atoms (group 18) are especially stable (you looked at the extreme stability of these gases in session 1) and that many elements ‘try to’ attain these configurations when forming compounds.
This is referred to as the octet rule.
What is the outer (valence) electronic configuration of the noble gases?
This can be represented as ns2np6, where n is the principle quantum number. Remember all the orbitals with the same value of n are said to be in the same shell, the point here is – the outer shell contains eight electrons (an octet), and is full.
These ideas were the brainchild of American chemist G.N. Lewis and will be considered in the next section.