Q28.In Li+ + ,electron in first Bohr orbit is excited to a level by a radiation of wavelength λ.When the ion gets de excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of λ ? (Given: ℎ= 6.63 × 10-34 J s ; 𝑐= 3 × 108 m s-1 ) (1) 10.8 nm (2) 9.4 nm (3) 11.4 nm (4) 12.3 nm
What This Question Tests
This problem requires determining the initial excited state of an electron from the total number of spectral lines observed and then calculating the wavelength of the exciting radiation.
Concepts Tested
Formulas Used
Number of spectral lines = n(n-1)/2
E_n = -13.6 Z²/n² eV
ΔE = hc/λ
📚 NCERT Sections This Tests
12.5 — A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,
Physics Class 12 · Chapter 12
12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
12.6 — (A) Using The Bohr’S Model Calculate The Speed Of The Electron In A
Physics Class 12 · Chapter 12
12.6 (a) Using the Bohr’s model calculate the speed of the electron in a hydrogen atom in the n = 1, 2, and 3 levels. (b) Calculate the orbital period in each of these levels.
12.3 — A Difference Of 2.3 Ev Separates Two Energy Levels In An Atom. What
Physics Class 12 · Chapter 12
12.3 A difference of 2.3 eV separates two energy levels in an atom. What is the frequency of radiation emitted when the atom make a transition from the upper level to the lower level?
📋 Question Details
- Chapter
- Atoms
- Topic
- Bohr Model and Atomic Spectra
- Year
- 2019
- Shift
- 10 Apr Shift 2
- Q Number
- Q28
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 12: Atoms
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