* Cobalt (Co) is a transition metal that can have multiple oxidation states.
* Chlorine (Cl) has a -1 charge in its ionic form.
* To balance the charges, cobalt must have a +3 oxidation state.
* The Roman numeral III in parentheses after "cobalt" indicates the +3 oxidation state.
Therefore, the full name of the compound is cobalt(III) chloride.