$K_{\alpha}$ and $K_{\beta}$ X-rays are emitted when there is a transition of electron between the levels

• Correct answer
  A

  $\mathrm{n}=2$ to $\mathrm{n}=1$ and $\mathrm{n}=3$ to $\mathrm{n}=1$ respectively
• B

  $\mathrm{n}=2$ to $\mathrm{n}=1$ and $\mathrm{n}=3$ to $\mathrm{n}=2$ respectively
• C

  $\mathrm{n}=3$ to $\mathrm{n}=2$ and $\mathrm{n}=4$ to $\mathrm{n}=2$ respectively
• D

  $\mathrm{n}=3$ to $\mathrm{n}=2$ and $\mathrm{n}=4$ to $\mathrm{n}=3$ respectively

Solution

When electron jumps from the level $\mathrm{n}=2$ to the level $\mathrm{n}=1, \mathrm{~K}_{\alpha} \mathrm{x}-$ rays are emitted. Similarly, $\mathrm{K}_{3}$ x-rays are emitted when there is atransition of electron from the level $\mathrm{n}=3$ to the level $\mathrm{n}=1$. X-ray spectra has been shown below.

Hence, the correct answer is option: 'A'.