I have a question about how I'm supposed to name (formula) the bond between a transition metal and a polyatomic ion. I know you'd first have to cross the charges of the ions, but for the transition metal (which has 2 common ion charges), how do you know which charge to use and bring down? How do you know which one to use without being given the compound name (example: Tin (ii) Nitrate) beforehand?

Basically, what do you do if you randomly pick them out from their tables (with no prior knowledge or resources) and decide to name their bond?