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 3 of 18
- A. Continuous
- B. Discrete
- C. Both a and b
- D. None of these
Explanation: The solar spectrum consists of a bright coloured continuous spectrum interspersed with dark lines so the answer is A.
Correct answer: Continuous- A. Alpha
- B. Infra-red
- C. Gamma
- D. All of these options are correct.
Explanation: Alpha particles are a type of nuclear radiation and consist of two protons and two neutrons, originating from the nucleus, not from…
Correct answer: Alpha- A. 10-6s
- B. 10-7 s
- C. 10-8 s
- D. 10-3 s
Explanation: The lifetime of atoms in an excited state refers to the time duration during which the electrons of the atoms will remain in their excited…
Correct answer: 10-8 s- A. He+
- B. Li++
- C. Ne+9
- D. Na10+
Explanation: Given that the wavelength of the atom is 1/4 of the wavelength of the hydrogen. Z = 2 and this is for Helium ion.
Correct answer: He+- A. Above 300 nm
- B. Below 300 nm
- C. In between UV and IR
- D. None of these
Explanation: Option C is correct since white light is visible light (between IR and UV), and it contains all the colors of the rainbow, from red to…
Correct answer: In between UV and IR- A. Line spectra
- B. Continuous spectra
- C. Absorption line spectra
- D. Emission line spectra
Explanation: Option C is correct since absorption line spectra occur when passing white light through cool, thin gas.
Correct answer: Absorption line spectra- A. Energy levels of the electrons are stable and discrete
- B. An electron emits or absorbs radiation only when making a transition from one energy level to another
- C. To jump from lower energy to higher energy, an electron must absorb a photon of precisely the right frequency such that the photon's energy equals the energy difference between the two orbits
- D. To jump from a higher energy to a lower energy, an electron absorbs a photon of frequency such that the photon's energy is exactly the energy difference between the two orbits
- E. None of the above
Explanation: Bohr's Model has quantised angular momentum, which is option A. It is consistent with the model.
Correct answer: To jump from a higher energy to a lower energy, an electron absorbs a photon of frequency such that the photon's energy is exactly the energy difference between the two orbits- A. 9.03 KeV
- B. 9.90 KeV
- C. 90.3 KeV
- D. 8.03 KeV
- E. 9.31 keV
Explanation: he energy difference between two levels can be calculated using the formula:ΔE = hc/λwhere h is Planck's constant, c is the speed of…
Correct answer: 9.31 keV- A. Optical physics
- B. Spectroscopy
- C. Atomic physics
- D. None of the above
Explanation: Spectroscopy is the branch of science devoted to discovering the chemical composition of materials by looking at the light (and other…
Correct answer: Spectroscopy- A. Rydberg
- B. Rontgen
- C. Planck
- D. None of the above
Explanation: X-rays were first discovered in 1895 accidentally by Rontgen. Rontgen reported the discovery after seven weeks of assiduous work during…
Correct answer: Rontgen- A. Characteristic x-rays
- B. Continuous x-rays
- C. Both A and B
- D. None of the above
Explanation: Minimum wavelength means maximum frequency, which means higher energy. Continuous X-rays have the highest energies.
Correct answer: Continuous x-rays- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: We know 1/λ= RH [1/p2 - 1/n2] where n=p-1 (n is higher state and p is lower state).
Correct answer: Option A- A. 3
- B. 6
- C. 15
- D. Infinite
Explanation: In hydrogen atom only one electron but infinite energy states so there are infinite spectral lines.
Correct answer: Infinite- A. 27 : 5
- B. 5 : 27
- C. 4 : 1
- D. 1 : 4
Explanation: The long wavelength limit of a series corresponds to the transition from the next highest energy level to the base level of the series.
Correct answer: 27 : 5- A. 8000 Ao
- B. 6563 Ao
- C. 1900 Ao
- D. None of the above
Explanation: For longest wavelength in the Balmer series, the transition takes place from n=3 to n=2.Longest wavelength 1/λ = 1.097 x 107 x(1/22-…
Correct answer: 6563 Ao- A. Less
- B. More
- C. Moderate
- D. None of the above
Explanation: The soft x-rays are the one which consist mostly of characteristic x-rays.
Correct answer: Less- A. A
- B. B
- C. C
- D. D
Explanation: Highest frequency in Lyman series when n=a,1/λ=RH [1/λ-0] = RH λ = 1. Also fλ =c.
Correct answer: C- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The explanation is given below: To find the frequency of the emitted radiation when an electron jumps from the 4th orbit to the 2nd orbit…
Correct answer: Option C- A. 9:5
- B. 5:36
- C. 1:4
- D. 3:4
Explanation: The Balmer series in the hydrogen atom's emission spectrum has different lines with varying wavelengths.
Correct answer: 9:5- A. Electron diffraction experiment of Davisson and Germer
- B. Thompson's measurement of e/m
- C. Young's double slit experiment
- D. Compton effect
Explanation: Evidence for the wave nature of matter is electron diffraction experiments of Davisson and Germer.
Correct answer: Electron diffraction experiment of Davisson and Germer