## Chemistry: The Molecular Science (5th Edition)

The $Cl$ atom has an oxidation number equal to $(+3)$, and each Fluorine atom has an oxidation number equal to $(-1)$.
According to the rule $6(a)$, a Fluorine atom has an oxidation number equal to (-1). According to rule $3$, if "x" is the oxidation number for the chlorine atom: $(x) * 1 + (-1) * 3 = 0$ x - 3 = 0 x = +3 The oxidation number for the chlorine atom in this compound is equal to $(+3)$.