Transition metal ionic compound questions

Question

SnF2: Why is it tin (II) fluoride? How do I get that?

MnO2: Why is it manganese (IV) oxide? How do I get that?

SnCl4: Why is it tin (IV) chloride? How do I get that?

Answer 1

F is 1- (group 7, XVII), so Sn must have 2+ charge to balance it. Thus, tin(II) fluoride

O is 2- (group 6, XVI), so the Mn must be 4+ to balance the 2 oxygens. Thus, manganese(IV) oxide

Cl is 1- (group 7, XVII) so the Sn must e 4+ to balance it. Thus, tin(IV) chloride. (compare this to the first one)