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 15 of 18
- A. [MLT-1]
- B. [ML2T-1]
- C. [ML2T-2]
- D. [ML2T2]
Explanation: The dimension of Planck's constant is M L² T⁻¹. This means that Planck's constant has units of energy multiplied by time, divided by mass…
Correct answer: [ML2T-1]- A. Kα
- B. Kβ
- C. Both A and B
- D. None of the above
Explanation: Kα corresponds to the low energy gap. Furthermore, it is easy for electrons to transfer from L to K shell than from M to K shell in Kβ.
Correct answer: Kα- A. 5.41 Å
- B. 4.20 Å
- C. 2.70 Å
- D. 1.35 Å
Explanation: Applying Moseley law: v =a(z−b) For multi electron system z will be (z−b) due to "shielding effect".
Correct answer: 5.41 Å- A. 5R/36
- B. 36R/5
- C. 36/5R
- D. 5/36R
Explanation: Explanation is given below: Longest wavelength or lowest frequency is emitted when p = 2 and n = 3.
Correct answer: 36/5R- A. Absorb energy
- B. Release energy
- C. No gain of energy
- D. None of these
Explanation: When an electron jumps from a higher energy level to a lower energy level (e.g., from the 3rd orbital to the 1st orbital), it releases…
Correct answer: Release energy- A. No gain of energy
- B. Release energy
- C. Absorb energy
- D. None of these
Explanation: When an electron jumps from low energy orbit to high energy orbit, it absorbs energy.
Correct answer: Absorb energy- A. V1 > v2 > v3
- B. V2 > v3 > v1
- C. V3 > v2 > v1
- D. V1 > v3 > v2
Explanation: As the frequency of the incident radiation increases, the potential required to stop the ejected electron , (Stopping Potential)…
Correct answer: V3 > v2 > v1- A. 1st orbit
- B. 3rd orbit
- C. 2nd orbit
- D. 4th orbit
Explanation: The Balmer series is a set of spectral lines in hydrogen atom's emission spectrum.
Correct answer: 2nd orbit- A. Infinite energy
- B. Minimum energy
- C. Maximum energy
- D. Zero energy
Explanation: The explanation for this question is given below: In Bohr's model lowest orbit corresponds to minimum energy.
Correct answer: Minimum energy- A. K.E increases, P.E decreases
- B. K.E decreases, P.E increases
- C. K.E increase, P.E increase
- D. K.E decrease, P.E decreases
Explanation: The explanation for this question is given below: When an electron goes from a lower orbit to a higher orbit, it absorbs energy to do so.
Correct answer: K.E decreases, P.E increases- A. λ/3
- B. 3λ/4
- C. 4λ/3
- D. 3λ
Explanation: When the photon transitions between energy levels 2E and E: E= 2E-E= EE= hc/λso, λ =hc/EWhen the photon transitions between energy levels…
Correct answer: 3λ- A. Line spectrum of atoms
- B. Diffraction by crystalline solids
- C. Production of X-rays
- D. Photo electric effect
Explanation: The wave-like nature of electrons is demonstrated by electron diffraction, where electrons create interference patterns similar to light…
Correct answer: Diffraction by crystalline solids- A. y-rays
- B. Visible light
- C. Infrared radiation
- D. Ultraviolet rays
Explanation: In an electronic transition the maximum energy photon can be emitted in x-ray region. y-rays can only be emitted in nuclear transition.
Correct answer: y-rays- A. Visible region
- B. Ultraviolet region
- C. Invisible region
- D. lnfra-red region
Explanation: The Balmer series corresponds to the set of spectral lines in the emission spectrum of hydrogen atoms that result from electron…
Correct answer: Visible region- A. They sat in a silence for a long time until Devin finally broke the silence.
- B. They sat in the silence for a long time until Devin finally broke the silence.
- C. They sat in silence for long time until Devin finally broke the silence.
- D. They sat in silence for a long time until Devin finally broke the silence.
Explanation: The sentence is structured correctly, using the phrase "in silence" and "for a long time" to convey the intended meaning.
Correct answer: They sat in silence for a long time until Devin finally broke the silence.- A. the Lyman series is a continuous spectrum
- B. the Paschen series is a line spectrum in the infrared region
- C. the Balmer series is a line spectrum in the ultraviolet region
- D. the spectral series formula can be derived from Rutherford's model of the hydrogen atom
Explanation: B is the correct option because The Paschen series consists of spectral lines in the infrared region of the electromagnetic spectrum.
Correct answer: the Paschen series is a line spectrum in the infrared region- A. 1.36eV
- B. 13.6eV
- C. 13.6Mev
- D. None of these
Explanation: Ionization energy will be equal to:Ei = Eo/(1)2 - Eo/(∞)2Ei = 13.6 - 0Ei = 13.6eV
Correct answer: 13.6eV- A. 8000 A°
- B. 6563 A°
- C. 1900 A°
- D. None of the above
Explanation: For the Balmer series, longest wavelength is from n=3 to n=2. Using 1/λ = 1.097 × 10^7 (1/2² - 1/3²), λ = 6563 Å.
Correct answer: 6563 A°- A. 8000 Å
- B. 6560 Å
- C. 1900 Å
- D. None of the above
Explanation: The longest wavelength in the Balmer series comes from the3 -> 2 transition.
Correct answer: 6560 Å- A. Charged pattern
- B. Fingerprint pattern
- C. Discharged pattern
- D. None of these
Explanation: Fingerprints are patterns specific to each person, therefore they can be used to identify individuals.
Correct answer: Fingerprint pattern