Question

What is the wavelength of light for the least energetic photon emitted in the Lyman series of the hydrogen spectrum. (take hc = 1240 eV nm)

• A. 122 nm
• B. 82 nm
• C. 150 nm
• D. 102 nm

Answer 1

The correct option is A

122 nm

$E=\frac{hc}{\lambda }\lambda =\frac{hc}{E}=\frac{1240}{10.2}\text{(for least energetic photon}E=E_2-E_1=10.2eV)\lambda \approx 122nm$