Bonds

INTRODUCTION

Chemical bonds form to lower the energy of the system, the components of the system become more stable through the formation of bonds. Thus formation of chemical bond is a way by which the energy of an atom (system) is reduced.
There are several types of chemical bond. Initially we will concern ourselves with three basic types, ionic bonding, which involves the transfer of electron(s), covalent bonding, which involves sharing of electrons and metallic bonding, which in some ways can be considered as a combination of both.
If we examine the periodic table, we find that the elements in Group VIII (or 18), helium, neon, argon and so on, are particularly stable, so much so that they were once labeled the "inert gases". We now know that these elements are not inert, indeed xenon forms a range of compounds, but, nevertheless, they are very stable (although now we refer to these elements as the noble gases). This stability is the result of their electronic configuration, they have a full valence shell of electrons and this imparts stability. G. N. Lewis (1916) suggested that bonds (covalent) formed to enable elements to attain this "noble gas configuration" and become stable.. We can extend this idea to ionic compounds, in a compound such as sodium chloride, one element loses electron(s) to gain this stable electronic configuration whilst the other gains electron(s) to achieve the same result. Thus the main objective/motive behind every attempt to make a chemical bond  is to gain stability and the electronic configuration of the stable NOBLE gases.This is done by any one of the following methods: