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 6 of 18
- A. its energy levels are too close to each other
- B. its energy levels are too far apart
- C. it has a very small mass
- D. it has a single electron
Explanation: A is the right option Here's why: The X-ray emission typically involves transitions between energy levels that are relatively far apart.
Correct answer: its energy levels are too close to each other- A. 1/4:
- B. 4/9
- C. 4
- D. 9/4
Explanation: D is the right option Here's why:Following the formula E = -R_H / n², we calculated the energy levels (E_2 and E_3) for the two states and…
Correct answer: 9/4103. In which region of the electromagnetic spectrum does the Lyman series of the hydrogen atom lie?
- A. infrared
- B. ultraviolet
- C. visible
- D. X-ray
Explanation: B is the right option Here's why:: The Lyman series of the hydrogen atom corresponds to transitions involving the principal quantum number…
Correct answer: ultraviolet- A. 1
- B. 3
- C. 2
- D. 4
Explanation: C is the right option Here's why: In Bohr's model, the Balmer series involves transitions of electrons from higher energy orbits to the…
Correct answer: 2- A. 4/3
- B. 9/5
- C. 9/4
- D. 16/7
Explanation: A is the right option Here's why:we used the Rydberg formula to find the approximate wavelengths for the longest and shortest transitions…
Correct answer: 4/3- A. decreases
- B. increases
- C. decreases for low Z and increases for high Z atoms
- D. remains constant
Explanation: A is the right option Here's why: With increasing quantum number, the energy difference between adjacent levels in atoms decreases.
Correct answer: decreases- A. current in the tube
- B. nature of the gas in the tube
- C. voltage applied to the tube
- D. atomic number of the target material
Explanation: D is the right option Here's why: The shortest wavelength of continuous X-rays emitted from an X-ray tube depends on the atomic number of…
Correct answer: atomic number of the target material- A. the intensity increases
- B. the intensity remains unchanged
- C. the minimum wavelength decreases
- D. both b & c
Explanation: D is the right option Here's why: When the potential difference applied to an X-ray tube is increased, both the intensity of the emitted…
Correct answer: both b & c- A. eh/V
- B. eV/h
- C. hV/e
- D. h/eV
Explanation: B is the correct option because The maximum frequency of X-rays emitted from an X-ray tube is given by the formula eV/h , where e is the…
Correct answer: eV/h- A. X-rays
- B. infrared rays
- C. ultraviolet rays
- D. visible light
Explanation: A is the correct option because X-rays are used to study the internal structure of crystals because they have wavelengths comparable to…
Correct answer: X-rays- A. mr=nh/2π
- B. mv= nh/2π
- C. mvr=h/2π
- D. mvr=nh/2π
Explanation: D is the correct option because According to Bohr's second postulate, the angular momentum of an electron in one of its orbits is…
Correct answer: mvr=nh/2π- A. En −Ep =f×λ
- B. En −Ep =h×e
- C. En −Ep =h×f
- D. Ep −En =h×f
Explanation: C is the correct option because The third postulate of Bohr's theory states that the difference between the energy of the final orbit (En…
Correct answer: En −Ep =h×f- A. 10^−6m
- B. 10^−8 m
- C. 10^−10m
- D. 10^−12 m
Explanation: C is the correct option because X-rays have wavelengths in the range of 10^−8 to 10^−12 meters, typically around 10^−10 meters.
Correct answer: 10^−10m- A. atom
- B. molecule
- C. matter
- D. nucleus
Explanation: Here's the explanation:Heisenberg's Uncertainty Principle:The uncertainty principle, also known as Heisenberg's uncertainty principle…
Correct answer: nucleus- A. Intense beam of light
- B. Coherent beam of light
- C. Monochromatic beam of light
- D. All of above
Explanation: Intense beam of light: Lasers produce light beams that are much more intense than those from other light sources, such as light bulbs or…
Correct answer: All of above- A. 6
- B. 4
- C. 10
- D. 3
Explanation: If an atom is in an excited state with the principal quantum number n = 5, the maximum number of transitions that can take place depends…
Correct answer: 10- A. ionized state
- B. stimulations
- C. population inversion
- D. all of these
Explanation: Of the listed options, only c. Population inversion accurately describes the situation where an excited state (metastable state) contains…
Correct answer: population inversion- A. Atom is mostly empty
- B. +ive charge is uniformly distributed in the atom
- C. Number of +ive charge is equal to the number of -ive charge
- D. Atoms contain electrons
Explanation: Correct. Rutherford's experiments showed that atoms have a mostly empty space.In summary, the correct option is **a.
Correct answer: Atom is mostly empty- A. Incandescent electric bulb
- B. Sun
- C. Mercury vapor lamp
- D. Candle
Explanation: Correct. Mercury vapor lamps produce discrete emission lines
Correct answer: Mercury vapor lamp- A. α rays
- B. β rays
- C. γ rays
- D. X rays
Explanation: Correct. The transitions of inner shell electrons in heavy atoms often result in the emission of γ raysCorrect.
Correct answer: γ rays