Question

What is the name of `SnO_2`?

Answer 1

Tin (IV) oxide.

Explanation:

IV, the Roman numeral for 4, refers to the oxidation state of the tin. Each oxygen atom in the oxide has its normal oxidation state of -2, you need the one Sn atom to be +4 to balance that.

This video provides some additional examples of how to use Roman numerals when naming compounds.