Answer: KMnO4
Explanation: Potassium K has a charge of +1 since it is a cation and in group 1. Permanganate is a polyatomic ion with a chemical formula of MnO4 - it is an anion with a -1 charge.
Do the criss cross rule on both charges and the result is KMnO4. The charge will cancel out since they are equal values.
