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:

Energy in Bohr's model is $E_n \propto \frac{1}{n^2}$. The first excited state is $n=2$, so $T_1 \propto \frac{1}{4}$. The second excited state is $n=3$, so $T_2 \propto \frac{1}{9}$. The ratio $T_1 : T_2 = \frac{1}{4} : \frac{1}{9} = 9:4$.