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 second excited state corresponds to $n=3$. The energy of this state is $E_3 = -\frac{13.6}{3^2} = -1.51 eV$. The energy required to remove the electron to infinity (ionization) is $0 - (-1.51) = 1.51 eV$.