Atomic Structure: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Atomic Structure. Understanding the underlying formula is key to arriving at the correct answer below:

The energy of the nth state is given by $E_n = \frac{-13.6}{n^2} eV$. The first excited state corresponds to $n=2$. Therefore, $E_2 = \frac{-13.6}{2^2} = -3.4 eV$.