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 17 of 18
- A. -13.6eV
- B. -1.51eV
- C. 3.40eV
- D. 0.54eV
Explanation: The energy of an electron in the excited state ( n=3 ) for a hydrogen atom can be calculated using the formula: En =−13.6/n2 eVPlugging in…
Correct answer: -1.51eV- A. Continuous spectra
- B. Band spectra
- C. Line spectra
- D. Braking radiation spectra
Explanation: Atoms produce line spectra. This is because atoms emit light at only specific wavelengths, producing a line spectrum rather than the…
Correct answer: Line spectra- A. 1
- B. 3
- C. 2
- D. 4
Explanation: An atom in an excited state can transition to any of the lower energy levels.
Correct answer: 3- A. 10-8s
- B. 10-3s
- C. 10-10s
- D. 10-6s
Explanation: Meta stable state is the state in which electrons stay for a longer duration (about10-3).
Correct answer: 10-3s- A. 21.7 x 10^-19 J
- B. 6.626 x 10^-34 J
- C. 5.425 x 10^-19 J
- D. 3664 x 10^-10 J
- E. 3 x 10^8 J
Explanation: The Balmer emission lines correspond to transitions down to the level for which n=2.
Correct answer: 5.425 x 10^-19 J- A. De-excitation
- B. Excitation
- C. Emission
- D. Conversion
Explanation: When an electron absorbs energy, it jumps to a higher orbital. This is called an excited state.
Correct answer: Excitation- A. randomly.
- B. continuously.
- C. when electrons change their orbits.
- D. when electrons become positively charged particle.
Explanation: * Bohr's model postulates that electrons exist in specific, fixed energy levels or orbits around the nucleus.
Correct answer: when electrons change their orbits.- A. emit energy.
- B. absorb energy.
- C. neither absorb nor emit energy.
- D. first absorb and then emit energy.
Explanation: When an electron in an atom jumps from a higher energy level to a lower energy level, it will A) emit energy.
Correct answer: emit energy.- A. line spectrum
- B. band spectrum
- C. absorption spectrum
- D. continuous spectrum
Explanation: The correct answer is 'line spectrum' because the radiations emitted by a hydrogen filled discharged tube result in a series of discrete…
Correct answer: line spectrum- A. attains the ground state
- B. attains the excited state
- C. becomes single ionized
- D. becomes double ionized
Explanation: When an atom emits X-rays, it does so by an electron transitioning from a higher energy level to a lower one, typically from an outer…
Correct answer: attains the ground state- A. I only
- B. III only
- C. I and II
- D. II and III
Explanation: The correct answer is III only. Spectral lines are emitted when electrons in a hydrogen atom transition from a higher energy level to a…
Correct answer: III only- A. Alpha particles.
- B. Beta particles.
- C. Cathode rays.
- D. Gamma rays.
Explanation: X-rays are a form of electromagnetic radiation, similar to gamma rays in that they both have high energy and short wavelengths.
Correct answer: Gamma rays.- A. Are diffracted by a crystal lattice.
- B. Pass through wood and flesh easily.
- C. Are deflected by electric and magnetic fields.
- D. Travel in a straight line with the velocity of light.
Explanation: The correct answer is that X-rays are not deflected by electric and magnetic fields.
Correct answer: Are deflected by electric and magnetic fields.- A. 10-6s
- B. 10-7s
- C. 10-8s
- D. 10-3s
Explanation: The atoms can remain in the excited state for 10^-8 sec and in the metastable state for 10^-3 sec.
Correct answer: 10-8s- A. Inner shell transition is possible
- B. Inner shell transition is not possible
- C. It is non-radioactive
- D. None of these options is correct
Explanation: The inner shells of the Sodium atom is already filled with a doublet and an octet configuration.
Correct answer: Inner shell transition is not possible- A. Electron
- B. Protons
- C. Alpha rays
- D. Any of these
Explanation: Ultraviolet radiation is produced by high-temperature surfaces, such as the Sun, in a continuous spectrum and by atomic excitation in a…
Correct answer: Electron- A. Orbital
- B. Spin
- C. Orbital & spin
- D. Orbital X spin
Explanation: Electrons have negative charge. When a charge spins, a magnetic field is created around it.
Correct answer: Spin- A. Stark Effect
- B. Zeeman Effect
- C. Photoelectric Effect
- D. Compton Effect
Explanation: Explanation: Splitting of spectral lines in closely spaced lines in presence of magnetic field is called Zeeman effect.
Correct answer: Zeeman Effect- A. 10-5 sec
- B. 10-3 sec
- C. 10-8 sec
- D. 10-2 sec
Explanation: Metastable states are characterized by their relatively longer lifetimes compared to typical excited states due to the stability they…
Correct answer: 10-3 sec- A. 2.19 x 10^7 m/sec
- B. 2.18 x 10^7 m/sec
- C. 2.2 x 10^8 m/sec
- D. 2.19 x 10^6 m/sec
Explanation: The velocity of an electron in the first orbit of hydrogen can be calculated using the Bohr model formula: v = n × h / (2π × m × r)…
Correct answer: 2.19 x 10^6 m/sec