JEE Mains · Physics · STD 12 - Atoms
- JEE Mains 2020
- Hard
- MCQ
The energy required to ionise a hydrogen like ion in its ground state is \(9\) Rydbergs. What is the wavelength of the radiation emitted when the electron in this ion jumps from the second excited state to the ground state ? ........\(nm\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(11.4 \)
Step-by-step Solution
Detailed explanation
\(1\) Rydberg energy \(=13.6 \mathrm{eV}\) So, ionisation energy \(=\left(13.6 \mathrm{Z}^{2}\right) \mathrm{eV}\)
\(=9 \times 13.6 \mathrm{eV}\)
\(z=3\)
\(\frac{1}{\lambda}=\mathrm{R} Z^{2}\left(\frac{1}{1^{2}}-\frac{1}{3^{2}}\right)=1.09 \times 10^{7} \times 9 \times \frac{8}{9}\)
\(\lambda=11.4 \mathrm{nm}\)
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