Question

A photon of wavelength 300 nm is absorbed by a gas and then reemitted as two photons. One photon is red with wavelength of 760 nm. The wave number of second photon will be

• A. 2.02 × 10⁶ m^-1
• B. 3.02 × 10⁶ m^-1
• C. 1.02 × 10⁶ m^-1
• D. 3.2 × 10⁶ m^-1

Answer 1

The correct option is A

2.02 × 10⁶ m^-1

$\frac{1}{\lambda }=\frac{1}{{\lambda }_1}+\frac{1}{{\lambda }_2}$

$\frac{1}{300}=\frac{1}{760}+\frac{1}{{\lambda }_2}$

$0.00333-0.001316=\frac{1}{{\lambda }_2}$

$\frac{1}{{\lambda }_2}=\overline{v_2}=2.0175\times {10}^{-3}nm$