This is a model of a lithium atom. how likely is it that this atom would want to bond with another atom to fill it's outer shell?

I'd say extremely likely. Lithium is in group 1 - they're all very reactive. Although it's the least reactive of the group, it's still very reaction and therefore very likely to react to have a full outer shell. It would bond through ionic bonding, transfer its outer electron (very easily). 

Hope this helps

Decomposition is the cycle at which bacteria breaks down any organic material into the soil