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 13 of 18
- A. Low; high
- B. High; low
- C. High; high
- D. Low; low
Explanation: A fluorescent lamp usually a tubular electric lamp has a coating of fluorescent material on its inner surface and containing mercury vapor…
Correct answer: High; low- A. λA = λB
- B. λA > λB
- C. λA < λB
- D. λA = 2λB
Explanation: Wavelengths of photons in a laser action are all the same hence the wavelength of A is equal to the wavelength of B.
Correct answer: λA = λB- A. Wavelengths
- B. Intensities of electromagnetic radiations emitted by atoms
- C. Intensities of electromagnetic radiations absorbed by atoms
- D. All of these options
- E. Both B and C
Explanation: Atomic spectra have different energy levels and electrons jump from one energy level to the other emitting and absorbing electromagnetic…
Correct answer: All of these options- A. Neon
- B. Hydrogen
- C. Carbon dioxide
- D. Sulphur dioxide
Explanation: For gaining atomic spectra, the evacuated glass tube is filled with hydrogen gas.
Correct answer: Hydrogen- A. AC
- B. DC
- C. Both A and B
- D. None of the above
Explanation: A DC X-ray machine uses direct electric current to power the X-ray tube head.
Correct answer: DC- A. Kα
- B. Kβ
- C. Both A and B
- D. None of the above
Explanation: The energy of Kα is given by:E(Kα) = EL - EKThe energy of Kβ is given by:E(Kβ) = EM - EKThus it is clear that:E(Kα) < E(Kβ)To give a quick…
Correct answer: Kβ- A. Radars
- B. CAT scans
- C. Finding out defects in structural steels
- D. None of the above
Explanation: X-rays, having an extremely high frequency and low wavelength, would not be suitable to use in radar systems because they would penetrate…
Correct answer: Radars- A. 5.41 Ao
- B. 4.20 Ao
- C. 2.70 Ao
- D. 1.35 Ao
Explanation: Applying Moseley law:v =a(z−b)For multi electron system z will be (z−b) due to "shielding effect".So, h₂/h₁ = (Z₂ - b)² / (Z₁ - b)²,h₂ = (…
Correct answer: 5.41 Ao- A. 0.85 eV
- B. 3.4 eV
- C. 13.6 eV
- D. 12.1 eV
Explanation: Third excited state means fourth energy state so electron have energy:Ionization energy= - En = -Eo/n2= -13.6/16 = - (-0.85 eV) = 0.85eV
Correct answer: 0.85 eV- A. 2
- B. 4
- C. 3
- D. 6
Explanation: No of spectral lines = n(n-1)/2 Here n=4, So 4(4-1)/2 = 6.
Correct answer: 6- A. One
- B. Three
- C. Two
- D. Four
Explanation: There are three emission spectra: Line Spectrum, Band Spectrum and Continuous Spectrum.
Correct answer: Three- A. Increases
- B. Decreases
- C. Unchanged
- D. May decreases or increases
Explanation: For Lyman series electron can transit from infinity to p=1 and for P-fund series electron can transit from infinity to p=5.
Correct answer: Decreases- A. 4/3R
- B. 1/R2
- C. C/R
- D. 1/RC
Explanation: The maximum wavelength of the Lyman series occurs when an electron in a hydrogen atom undergoes a transition from the n=2 energy level to…
Correct answer: 4/3R- A. (E0 -E1) / hc
- B. E1/hc - E0 / hc
- C. (E1 - E0)/ h
- D. hc/ (E1 - E0)
Explanation: When an atom is excited from its ground state energy level Eo to an excited state energy level E1, it can then return to the ground state…
Correct answer: hc/ (E1 - E0)255. Which of the transitions in hydrogen atom emits a photon of lowest frequency (n=quantum number):
- A. n = 2 to n = 1
- B. n = 4 to n = 3
- C. n = 3 to n = 1
- D. n = 4 to n = 2
Explanation: As we go to higher states the energy difference between the consecutive states decreases so photon of lowest frequency is obtained when it…
Correct answer: n = 4 to n = 3- A. 3R/4
- B. 3/4R
- C. 4/3R
- D. 4/3
Explanation: When an electron in the hydrogen atom transitions from a higher energy state (n = 2) to a lower energy state (n = 1), it emits a photon.
Correct answer: 4/3R- A. 4/R
- B. R/4
- C. 1/4R
- D. 4
Explanation: In the Balmer series, the shortest wavelength photon is emitted when an electron transitions from the n=3 energy level to the n=2 energy…
Correct answer: 4/R- A. 2
- B. 4
- C. 3
- D. Both A and C
Explanation: The Balmer series involves transitions where the electron falls to the second energy level (n=2) from higher levels (n=3, n=4, etc.).
Correct answer: 3- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The Paschen series, which represents spectral lines in the emission spectrum of hydrogen, can be described by the Rydberg formula, just…
Correct answer: Option C- A. Paschen series
- B. Balmer series
- C. Pfund series
- D. Lyman series
Explanation: The spectral series that contains transition terminating on the ground state (lowest energy level) of a hydrogen atom is called the "Lyman…
Correct answer: Lyman series