# Math Help - Univ. Chemistry Word Problem -- Atomic Properties

1. ## Univ. Chemistry Word Problem -- Atomic Properties

An excited hydrogen atom emits light with a frequency of 1.141 multiplied by 1014 Hz to reach the energy level for which n = 4. In what principal quantum level did the electron begin?

2. 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 $n_{i}$.