# What is the formula mass of the iodine molecule?

Iodine is a diatomic molecule, and we work out the mass of ${I}_{2}$.
The atomic mass of iodine is $126.9 \cdot g \cdot m o {l}^{-} 1$ (from where did I get that figure?), and thus its formula mass is $253.8 \cdot g \cdot m o {l}^{-} 1$.