Free Atomic Spectra MCQs with Answers
356 Atomic Spectra MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atoms emit or absorb light at specific wavelengths because electrons occupy quantized energy levels and change levels by absorbing or releasing photons. The topic covers emission and absorption spectra, spectral series, hydrogen’s line spectrum, energy-level transitions, and the relation between wavelength, frequency and photon energy.
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Read the Atomic Spectra notesFree MDCAT chapter notes with key terms356 questions · page 14 of 18
- A. 2nd orbit
- B. 4th orbit
- C. 3rd orbit
- D. 5th orbit
Explanation: The Paschen series is obtained when all the transitions of an electron in a hydrogen atom terminate on the n = 3 energy level.
Correct answer: 3rd orbit- A. 1
- B. 7
- C. 5
- D. 10
Explanation: Total no. of spectral lines (from n=5 to n=1) = 4+3+2+1 = 10
Correct answer: 10- A. 1st to 5th orbit
- B. 3rd to 5th orbit
- C. 2nd to 5th orbit
- D. 4th to 5th orbit
Explanation: Photon of high frequency will be absorbed when transition takes place from 1st to 5th orbit because the energy difference is maximum than…
Correct answer: 1st to 5th orbit- A. 36 / 5
- B. 6 / 5R
- C. 5R / 36
- D. 5R / 6
Explanation: For the transition 3 to 2, use the Rydberg formula:1/lambda= R (1/4 - 1/9) = R (5/36) so lambda= 36/5R
Correct answer: 36 / 5- A. [ML-2]
- B. [L-1]
- C. [ML-1]
- D. [ML-1T-1]
Explanation: Rydberg constant has units of per metre so [RH] = [L-1]
Correct answer: [L-1]- A. Red
- B. Green
- C. Yellow
- D. Blue
Explanation: The light photon with the least momentum is red. This is because red light has the longest wavelength of all visible light.
Correct answer: Red- A. (2. 1)
- B. (∞, 1)
- C. (3, 2)
- D. (∞, 2)
Explanation: For Balmer series electron should jump from any higher energy level to 2nd energy level. For this (m, n) = (∞,2 )
Correct answer: (∞, 2)- A. 4K
- B. K/2
- C. 2K
- D. K/4
Explanation: For a free electron, its wavelength increases when its momentum and kinetic energy drop.
Correct answer: K/4- A. RH/4
- B. RH/9
- C. 4/RH
- D. 9RH
Explanation: In the Balmer series, the shortest wavelength comes from the limiting transition (infinity to 2 ). Using the Rydberg formula lambda=4/RH.
Correct answer: 4/RH- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The Paschen series includes all transitions that end at level n = 3. The longest wavelength happens when the electron loses the least…
Correct answer: Option D- A. 1, 2, 3
- B. 2, 3, 1
- C. 3, 2, 1
- D. 2 1, 3
Explanation: E = Φ + K.Ehf= Φ + VseIf Vs = 0Φ=hfo ⇒ Φ ∝ foΦ1<Φ2<Φ3
Correct answer: 1, 2, 3- A. 0
- B. 9.1 eV
- C. 1.5 eV
- D. 12.1 eV
Explanation: 2nd excited means 3rd energy level (n = 3). Ground state is −13.6 eV.Energy of emitted photon = E_initial − E_final= (−1.51 eV) − (−13.6…
Correct answer: 12.1 eV- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The Brackett series gets its longest wavelength from the smallest energy jump, which happens when an electron moves from level 5 down to…
Correct answer: Option D- A. Lyman series
- B. Balmer series
- C. Paschen Series
- D. Brackett series
Explanation: A wavenumber of Rh over 9 means the electron is ending on the third energy level.
Correct answer: Paschen Series- A. Lyman series
- B. Paschen series
- C. Pfund series
- D. Brackett series
Explanation: Lyman series lies in ultra violet region.Balmer series lies in visible region.Paschen series lies in infra red region.Brackett series lies…
Correct answer: Lyman series- A. 2nd orbit to 1st orbit
- B. 5th orbit to 2nd orbit
- C. 10th orbit to 3rd orbit
- D. 20th orbit to 4th orbit
Explanation: The largest energy difference between nearby levels occurs from n = 2 to n = 1.
Correct answer: 2nd orbit to 1st orbit- A. -13.60eV
- B. -0.8eV
- C. -3.40eV
- D. -1.51 eV
Explanation: The total energy of an electron in the fourth orbit of a hydrogen atom is negative because it is bound to the nucleus.
Correct answer: -0.8eV- A. Bound spectrum
- B. Continuous spectrum
- C. Line spectrum
- D. Absorption spectrum
Explanation: A line spectrum which consists of discrete lines corresponding to single wavelength or frequency of emitted or absorbed radiation is…
Correct answer: Line spectrum- A. Ultraviolet rays
- B. Infrared radiation
- C. X-rays
- D. Visible radiations
Explanation: The wavelength of infrared radiation is greater than visible light. So, the radiation with wavelength greater than red light is infrared.
Correct answer: Infrared radiation- A. 25/9
- B. 9/5
- C. 17/6
- D. 4/3
Explanation: The longest wavelength corresponds to the 5 → 4 transition, and the shortest corresponds to ∞ → 4.
Correct answer: 25/9