Question

 The “octet” rule appears to be a very important rule governing the structures of molecules. In light of your work with models, provide a simple explanation for the importance of 8 electrons

Answer 1

The octet rule refers to the sharing of electrons in covalent compounds. The compounds form in the firstly because the products will be at a lower total energy than the reactants. This is what makes the octet "stable". The octet comes from the filled s and p sublevels, like that of an inert gas and for the halide ions.
In atoms with an outer shell containing SP electrons, the most stable state is when the number of S electrons is 2 and the P electrons are 6
This may be achieved by giving or receiving electrons ( ionic bonds ) or sharing electrons ( covalent bonds )

For Example: The noble gases rarely form compounds. They have the most stable configuration (full octet, no charge), so they have no reason to react and change their configuration. All other elements attempt to gain, lose, or share electrons to achieve a noble gas configuration.

so this means, atoms will react to get in the most stable state possible. A complete octet is very stable because all orbitals will be full. Atoms with greater stability have less energy