Forming a Nucleophile Bond

[TeaK1C]

In lecture, when a nucleophile was added to the structure H-C-Cl-H, the C-Cl bond was broken in the process. Did this happen because carbon can only have 4 bonds or do you always have to break a bond when you form another bond with the nucleophile?

[Saitiel1]

Yes, the bond C-Cl bond was broken because there should only be a maximum of four bonds. Carbon's outer shell can only hold 8 electrons.