There's no "for formula" for Sn1O2. It seems you might be asking about the formula of tin(II) oxide.

Here's the explanation:

* Sn represents tin, and its Roman numeral II indicates it has a +2 charge.

* O represents oxygen, which typically has a -2 charge.

Since the charges are already balanced, the simplest whole-number ratio of tin to oxygen is 1:1. Therefore, the correct formula for tin(II) oxide is SnO.

The formula Sn1O2 doesn't exist in a stable compound.