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 18 of 18
- A. Protons
- B. Electrons
- C. Neutrons
- D. Alpha particles
Explanation: X rays are produced due to electrons. When a heated filament emits electrons by thermionic emission in a glass envelope.These electrons…
Correct answer: Electrons- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The given graph in option A represents the observed intensity of the X-rays emitted by an X-ray tube as a function of wavelength.
Correct answer: Option A- A. Characteristics of X-rays
- B. Bremsstrahlung X-ray
- C. Soft X-ray
- D. Hard X-ray
Explanation: Continuous X-rays are created when free-moving electrons electromagnetically interact with nuclei.
Correct answer: Bremsstrahlung X-ray- A. Equal to the X-rays
- B. Longer to the X-rays
- C. Shorter than the X-rays
- D. border to the X-rays
Explanation: Gamma rays are electromagnetic radiation with the shortest wavelength and highest energy.
Correct answer: Shorter than the X-rays- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The atom is excited to an energy level Ei from its ground state energy level Eo, the wavelength of the radiation emitted is given as…
Correct answer: Option C- A. 0.54eV
- B. 0.85eV
- C. 3.39eV
- D. 13.6eV
Explanation: The ionization energy for hydrogen is 2.18 x 10-18 Joules which when divided by 1.60 x 10-19 Joules/eV gives us 13.6 eV.
Correct answer: 13.6eV- A. Neon
- B. Nitrogen
- C. Helium
- D. Oxygen
Explanation: A tube containing charged electrodes and filled with a gas in which ionization is induced by an electric field.
Correct answer: Helium- A. The radius of the orbits are integral multiple of the Bohr-radius ...... 0.053mm
- B. The angular momentum is n times h/2π
- C. The energy in the nth-orbit is n times the ground state energy.
- D. Missing
Explanation: This option is correct as the angular momentum is n times h/2pi which is given by the formula : L=nh/2pi or mvr=nh/2pi which is stated in…
Correct answer: The angular momentum is n times h/2π- A. 8
- B. 4
- C. 6
- D. 10
Explanation: The transition of a hydrogen atom from the ground state to an energy level characterized by n = 4 corresponds to an electron moving from…
Correct answer: 6- A. 10^-35 sec
- B. 10^-8 sec
- C. 10^-3sec
- D. 0.1 sec
Explanation: The lifetime of an ordinary excited state refers to the time it takes for an atom or molecule to transition from the excited state back to…
Correct answer: 10^-8 sec- A. 10^3
- B. 10^5
- C. 100
- D. 10^8
Explanation: This option corresponds to the correct answer, indicating a much longer lifetime for an electron in a metastable state compared to an…
Correct answer: 10^8352. The wavelength,of last spectral line in Lyman series in terms of Rydberg constant(R) is equal to:
- A. R
- B. R2
- C. 1/R
- D. 1/R2
Explanation: The last line of a series is its series limit, where the electron falls from n = infinity.
Correct answer: 1/R- A. Balmer series
- B. Lyman series
- C. Paschen series
- D. Pfund series
Explanation: Transitions that end on the third orbit produce the Paschen series, which lies in the infrared.
Correct answer: Paschen series- A. RH/9
- B. 9/RH
- C. 9 RH
- D. 9 + RH
Explanation: The shortest wavelength in a series is its series limit, where the electron falls from n = infinity.
Correct answer: 9/RH- A. Visible region
- B. Infrared region
- C. Ultraviolet region
- D. X-rays
Explanation: The Lyman series ends on n = 1, the largest energy drop of any hydrogen series, so its photons are the most energetic and shortest in…
Correct answer: Ultraviolet region- A. Visible
- B. Ultraviolet
- C. Infrared
- D. None of the above
Explanation: Transitions ending on the second orbit form the Balmer series, and the Balmer lines fall in the visible region.
Correct answer: Visible