Another Homework Thread

Heya. I'm a Year 12 Chem student, doing Redox atm. I was calculation the oxidation numbers of atoms given a species, and getting them mostly right, when disaster struck.

(ClO2)-

That's a subscript two, and a negative charge.
The answers say +3. I think it's +5, because each Oxygen has a -2 and it's got a single negative charge, so -2*2-1=-5, the Cl must be +5 to balance the charge. Please tell me why I'm wrong.

(ClO₂)^-

The charge of an ion isn't supposed to be balanced.
+3 + -2*2 = -1.

I wants lots and lots of some delectable pot!

Marijuana MUST be legalized.