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.
Last updated
Read the Atomic Spectra notesFree MDCAT chapter notes with key terms356 questions · page 16 of 18
- A. Several discrete series of lines with both intensity and spacings between lines decreasing as the wavenumber increases with each series
- B. A continuous spectrum with no distinct lines
- C. A few broad, overlapping lines
- D. A single, sharp line
Explanation: This is the correct answer. The emission spectrum of atomic hydrogen is characterized by several distinct series of lines, each…
Correct answer: Several discrete series of lines with both intensity and spacings between lines decreasing as the wavenumber increases with each series- A. Minimum energy
- B. Maximum energy
- C. Zero energy
- D. Cannot be determined
Explanation: This is the correct answer. The ground state of an atom is the lowest energy state that its electrons can occupy.
Correct answer: Minimum energy- A. Its energy levels are too close to each other
- B. Its energy levels are too far apart
- C. It is too small in size
- D. It has a single electron
Explanation: Its energy levels are too far apart - Correct: X-rays are produced when high-energy transitions occur, typically in atoms with many…
Correct answer: Its energy levels are too far apart- A. 11097 A
- B. 18750
- C. 17884 A
- D. 19001 A
Explanation: The solution as followsn=3, m=4. Longest wavelength (λL) =? 1/λL= R (1/n2 -1/m2) 1/λL= R(1/32 -1/42)= R(1/9-1/16)1/λL= 1.097x107…
Correct answer: 18750- A. 1 ns
- B. 2 ns
- C. 3 ns
- D. All of these options are correct
Explanation: An atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption.
Correct answer: 1 ns- A. 1 ns
- B. 2 ns
- C. 3 ns
- D. All of these
Explanation: Excited atoms return to their ground state in 1ns.
Correct answer: 1 ns- A. Kα X-Ray
- B. Kß X-Ray
- C. Kγ X-Ray
- D. All of these option have the same intensity
Explanation: Alpha rays are the positively charged particles. Alpha-particle is a highly active and energetic helium atom that contains two neutrons…
Correct answer: Kα X-Ray- A. Cathode rays
- B. Canal rays
- C. Gamma rays
- D. Beta rays
Explanation: Option A: Cathode rays are streams of electrons that are emitted from a cathode, which is a negatively charged electrode.
Correct answer: Gamma rays- A. Characteristic x-ray
- B. Continuous x-rays
- C. Both A and B
- D. None of the above
Explanation: Continuous x-rays are released when electrons loose energy, thus, possess more energy than characteristic x-rays.
Correct answer: Continuous x-rays- A. 1st to 5th orbit
- B. 5th to 1st orbit
- C. 3rd to 5th orbit
- D. 4th to 5th orbit
Explanation: Photons of highest frequency are absorbed when an electron transitions to higher energy level from lower energy level occurs.
Correct answer: 1st to 5th orbit- A. 4thorbit
- B. 3rdorbit
- C. 5th orbit
- D. 2nd orbit
Explanation: Bracket series is obtained when all transition of electron terminate on 4th orbit
Correct answer: 4thorbit- A. UV
- B. Visible
- C. Infrared
- D. None of the above
Explanation: Balmer series is displayed when electron transition takes place from higher energy states (nh=3,4,5,6,7,...) to nl=2 energy state.
Correct answer: Visible- A. 22/RH
- B. 32/RH
- C. 42/RH
- D. 52/RH
Explanation: The mathematical formula for the Pfund series is: 1/λ = RH (1/52 -1/n2) For shortest wavelength n=∞ 1/λ = RH (1/52 -1/∞2) 1/λ = RH / 52 λ…
Correct answer: 52/RH314. When a hydrogen atom is in its first excited level, what is the relation of radius and Bohr radius?
- A. Twice
- B. 4 times
- C. Same
- D. Half
Explanation: For the first excited level, n = 2. r2= (2)2r0 = 4r0. So, when a hydrogen atom is in its first excited level, its radius is 4 times of the…
Correct answer: 4 times- A. Option A
- B. Option C
- C. Option D
Explanation: Highest frequency in Lyman series when n=a, 1/λ=RH [1/λ-0] = RH λ = 1. Also fλ =c.
Correct answer: Option C- A. 5:9
- B. 5:36
- C. 1:4
- D. 3:4
Explanation: The explanation is given below: The Balmer series in the hydrogen atom's emission spectrum has different lines with varying wavelengths.
Correct answer: 5:9- A. 4thorbit
- B. 3rdorbit
- C. 5th orbit
- D. 2ndorbit
Explanation: Bracket series is obtained when all transition of electron terminate on 4th orbit
Correct answer: 4thorbit- A. 1st to 5th orbit
- B. 2nd to 5th orbit
- C. 3th to 5th orbit
- D. 4th to 5th orbit
Explanation: If energy gap is maximum then energy required will also be maximum.
Correct answer: 1st to 5th orbit319. Which of the following series of hydrogen spectra lies in the ultraviolet region of the spectrum?
- A. Lyman series
- B. Balmer series
- C. Paschen series
- D. Pfund series
Explanation: The series of the hydrogen spectrum that lies in the ultraviolet region is the Lyman series.
Correct answer: Lyman series320. lf an electron jumps from the second orbit to first orbit in hydrogen atom, it emits photon of:
- A. 3.04 eV
- B. 10.20 eV
- C. 13.6 eV
- D. 3.8 eV
Explanation: When an electron in a hydrogen atom transitions from the second orbit (n=2) to the first orbit (n=1), it emits a photon with a specific…
Correct answer: 10.20 eV