WBJEE · Physics · Atomic Physics
A sample of hydrogen atom in its ground state is radiated with photons of \(10.2 \mathrm{eV}\) energies. The radiation from the sample is absorbed by excited ionized \(\mathrm{He}^{+}\). Then which of the following statement/s is / are true ?
- A \(\mathrm{He}^{+}\)electron moves from \(n=2\) to \(n=4\)
- B In the \(\mathrm{He}^{+}\)emission spectra, there will be 6 lines
- C Smallest wavelength of \(\mathrm{He}^{+}\)spectrum is obtained when transition taken place from \(n=4\) to \(n=3\)
- D \(\mathrm{He}^{+}\)electron moves from \(n=2\) to \(n=3\)
Answer & Solution
Correct Answer
(C) Smallest wavelength of \(\mathrm{He}^{+}\)spectrum is obtained when transition taken place from \(n=4\) to \(n=3\)
Step-by-step Solution
Detailed explanation
\(\begin{gathered} E=13.6 \times 2^2\left(\frac{1}{n^2}-\frac{1}{m^2}\right) \\ n=2 \text { to } m=4 \\ E=13.6 \times 2^2 \times\left(\frac{1}{2^2}-\frac{1}{4^2}\right)=10.2 \mathrm{eV} \end{gathered}\) So \(\mathrm{He}^{+}\)electron can move from \(n=2\) to \(n=4\) Number of…
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