Question

What should be the frequency (in cycles per second)
of the emitted radiation when an electron undergoes
urahistuon from M energy level to K energy level, if
the value of R is 10^5 cm- oder :
(A) 3/2 x 10^16 (B) 8/3 * 10^15
(C) 8/5 x 10^15 (D) 9/4 * 10^15​

Answer 1

Answer:

The frequency  of the emitted radiation $\frac{8}{3}\times 10^{15} s^{-1}$.

Explanation:

In Bohr structure of atom, electrons revolve around in fixed orbits which he named shells or energy levels.

K=1, L=2, M=3, N=4.....

According to question, electron is going form M to K that is from third energy level to first energy level.

$n_i=3 \rightarrow n_f=1$

$\frac{1}{\lambda }=R[\frac{1}{n_i^{2}}-\frac{1}{n_f^{2}}]$

R= Rydberg constant =[tex}R=10^{5} cm^{-1}[/tex]

$\frac{1}{\lambda }=10^{5} cm^{-1}[\frac{1}{3^2}-\frac{1}{1^2}$

$\lambda =\frac{9\times 10^{-5}}{8} cm= \frac{9\times 10^{-7}}{8} m$

$\nu=\frac{c}{\lambda }$

$\nu=\frac{3\times 10^8 m/s}{\frac{9\times 10^{-7}}{8} m}$

$\nu=\frac{8}{3}\times 10^{15} s^{-1}$

The frequency  of the emitted radiation $\frac{8}{3}\times 10^{15} s^{-1}$.