Question

The transition from from the state $n=5$ to $n=1$ in a hydrogen atom results in $UV$ radiation. Infrared radiation will be obtained in the transition.

• A. $2\to 1$
• B. $3\to 2$
• C. $4\to 3$
• D. $6\to 2$

Answer 1

The correct option is C $4\to 3$

$\frac{1}{\lambda }=R(\frac{1}{n_1^2}-\frac{1}{n_2^2})$

for UV $n_1=1$ and $n_2=5$, $\lambda =\frac{1.04}{R}$

for infrared the wavelength must be greater the UV wavelength.

For $n_1=3$ and $n_2=4$ , $\lambda =\frac{7.2}{R}$. This is the largest wavelength we can get