# Exercise 5 | Early Quantum Theory

What is the initial energy level when an electron of a hydrogen atom transitions into n = 2 and emits a photon at 410 nm?

Ephoton = $\frac{\mathrm{hc}}{\mathrm{\lambda }}$

and Ephoton =

⇒     = -0.222

= 2.76 x 10-2

⇒ ni = 6