In a mixture of – gas

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

In a mixture of

\text{H}

–

\text{He}^+

gas,

\text{H}

atoms and

\text{He}^+

ions are excited to their respective first excited states. Subsequently,

\text{H}

atoms transfer their total excitation energy to

\text{He}^+

ions by collisions. Assume that the Bohr model is exactly valid. The wavelength of visible light emitted by

\text{He}^+

ions after collisions with

\text{H}

atoms is: (1)

6.5\times10^{-7}\text{ m}

(2)

5.6\times10^{-7}\text{ m}

(3)

4.8\times10^{-7}\text{ m}

(4)

4.0\times10^{-7}\text{ m}