Question

Calculate the wavelength of radiations emitted, produced in a line in Lyman series, when an electron falls from fourth stationary state in hydrogen atom.
$(R_H=1.1\times {10}^7{m}^{-1})$.

Answer 1

$\frac{1}{\lambda }=R(\frac{1}{n_1^2}-\frac{1}{n_2^2})$
$=1.1\times {10}^7(\frac{1}{1^2}-\frac{1}{4^2})$
$=969.6\times {10}^{-10}$ metre
$\therefore$ $\lambda =969.6\mathring{A}$.