In the Lyman series of hydrogen,which are the two maximum wavelengths? Why?

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) The wavelength $\lambda$ for the hydrogen spectrum is given by the Rydberg formula: $\frac{1}{\lambda} = R_H \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right)$.
For the Lyman series,$n_1 = 1$. The wavelength is inversely proportional to the energy difference $\Delta E = E_{n_2} - E_{n_1}$.
To obtain the maximum wavelengths,we need the minimum energy transitions,which correspond to the smallest values of $n_2$ above $n_1$.
For $n_2 = 2$,$\frac{1}{\lambda_1} = R_H (1 - \frac{1}{4}) = \frac{3}{4} R_H$,giving $\lambda_1 \approx 121.6 \ nm$.
For $n_2 = 3$,$\frac{1}{\lambda_2} = R_H (1 - \frac{1}{9}) = \frac{8}{9} R_H$,giving $\lambda_2 \approx 102.6 \ nm$.
Thus,the two maximum wavelengths correspond to transitions from $n_2 = 2$ and $n_2 = 3$ to $n_1 = 1$.

Explore More

Similar Questions

Number of spectral lines obtained in $He^{+}$ spectra,when an electron makes transition from fifth excited state to first excited state will be

The energy of an electron in a hydrogen atom in its ground state is $-13.6 \ eV$. The energy of the level corresponding to the quantum number equal to $5$ is ............. $eV$.

The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is $.... \times 10^{-19} \, J$
[Given: The threshold frequency of platinum is $1.3 \times 10^{15} \, s^{-1}$ and $h = 6.6 \times 10^{-34} \, J \, s$.]

Calculate the energy associated with the third orbit of $He^{+}$.

Which of the following statements are correct?
$I$) The energy of hydrogen atom in its ground state is $-13.6 \ eV$
$II$) On the basis of Bohr's model,the radius of the $3^{rd}$ orbit of hydrogen atom is $158.7 \ pm$
$III$) The order of radius of the first orbit of $H, He^{+}, Li^{2+}$ and $Be^{3+}$ is $H > He^{+} > Li^{2+} > Be^{3+}$

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo