# Univ. Chemistry Word Problem -- Atomic Properties

Balmer's formula: $\frac{1}{\lambda} = R \left(\frac{1}{n_{f}^2} - \frac{1}{n_{i}^2}\right)$
You have $\frac{1}{\lambda}$ (can figure out the frequency), R (the Rydberg constant), and $n_{f}$ the final energy level of the electron.
Just a matter of algebra from here to solve for $n_{i}$.