Post 1 Chemcial Bonding

Our newest lecture is over chemical bonding which involves the type of bonds as well as the shape of those elements as they bond. In covalent bonds, where bonds are shared rather than given or taken, elements can not be between a cation and an anion as this is an ionic bond, and thus this lecture doesn't apply.
First, when given a formula, make a have need share box in which:
H is the number of the element in that bond times the valence number (found in the periodic table).
N comes from the total electrons needed to be stable so you take the number of the element times 7 (where elements become stable but there are exceptions).
S determines how many bonds necessary by taking the added number of needs minus the added number of haves before dividing it by two because all bonds come in pairs of electrons.

The exceptions are:
H, He, Be = 2e-, B = 6e-, and elements in period 3 and beyond can have expanded octets including the major ones, the non-metals S, P, Xe, and Kr.

Here's some links to get into the unit:
hyperphysics