Question

The wavelength (in $\mathring{A}$) of an emission line observed for $L{i}^{2+}$ during electronic transition from $n_2=2$ to $n_1=1$ is: ($R$ is Rydberg constant)

• A. $\frac{4}{27R}$
• B. $\frac{27R}{4}$
• C. $\frac{4}{3R}$
• D. $\frac{3R}{4}$

Answer 1

The correct option is C $\frac{4}{3R}$

$1/\lambda =R(1/n_1^2-1/n_2^2)z^2$

$1/\lambda =R(1/1^2-1/2^2)$

$1/\lambda =R\left(3/4\right)$

$\lambda =4/3R$