Question

If the electron in a hydrogen atom jumps from an orbit with level $n_{1} =2$ to an orbit with level $n_{2} =1$ the emitted radiation has a wavelength given by

• A. $\lambda = \frac{5}{3R}$
• B. $\lambda = \frac{4} {3R}$
• C. $\lambda = \frac{R}{4}$
• D. $\lambda = \frac{3R}{4}$

Answer 1

Answer: (B)

$\lambda = \frac{4} {3R}$

Answer 2

$\frac{1}{\lambda}=R \left(\frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}}\right)$
$=R\left(\frac{1}{1^{2}}-\frac{1}{2^{2}}\right)=\frac{3R}{4}$
$\Rightarrow\, \lambda =\frac{4}{3R}$