Free Atomic Structure MCQs with Answers
922 Atomic Structure MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Atomic structure covers the discovery of the proton, Planck's quantum theory, hydrogen emission spectra and the evidence for quantized energy levels. You will use quantum numbers to describe orbitals, distinguish s, p, d and f orbital shapes, and write electronic configurations, including the correct order of electron filling.
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922 questions · page 6 of 47
- A. H+ H H-
- B. Li+ Na+ K+
- C. C1- Br- I
- D. F- Ne Na+
Explanation: Isoelectronic species have the same number of electrons. F- has 9 + 1 = 10 electrons, Ne has 10 electrons, and Na+ has 11 - 1 = 10…
Correct answer: F- Ne Na+- A. tritium
- B. deuterium
- C. protium
- D. ortho-hydrogen
Explanation: Tritium is hydrogen-3, containing one proton and two neutrons, and it is radioactive.
Correct answer: tritium- A. reflection
- B. interference
- C. diffraction
- D. refraction
Explanation: When light enters a prism, it changes speed at the boundary between air and glass and bends, which is refraction.
Correct answer: refraction- A. Ultra voilet
- B. Gamma rays
- C. Infrared
- D. All of these
Explanation: The Earth receives much of the Sun’s incoming energy in visible and shorter-wavelength radiation, but its cooler surface emits mainly…
Correct answer: Infrared- A. 159.6kJ
- B. 135.5 KJ
- C. 110.5 KJ
- D. 80.4 KJ
Explanation: The energy of one photon is E = hν, so the energy of one mole is E = NAhν = (6.022 x 10^23 mol-1)(6.626 x 10^-34 J s)(4 x 10^14 s-1) =…
Correct answer: 159.6kJ- A. Spectrophotometer method
- B. Dilatometric method
- C. Optical relation method
- D. Refractometric method
Explanation: A spectrophotometer measures how much radiation a substance absorbs at selected wavelengths, usually by comparing incident and transmitted…
Correct answer: Spectrophotometer method- A. Moseley
- B. Davisson and Germer
- C. Einstein
- D. Roentgen
Explanation: Davisson and Germer verified the wave nature and de Broglie wavelength of electrons by observing electron diffraction from a nickel…
Correct answer: Davisson and Germer- A. Is independent of wavelength
- B. Depends upon source
- C. Depends upon its frequency
- D. Equals to the square of amplitude
Explanation: In a vacuum, every photon travels at the constant speed of light, c, regardless of its wavelength or frequency.
Correct answer: Is independent of wavelength109. The relationship between energy of a photon of light and its frequency is given by________________?
- A. de-Broglie duel nature of matter
- B. Bohrs model
- C. Plancks Quantum theory
- D. Rutherfords atomic model
Explanation: Planck's quantum theory gives the photon-energy relation E = hν, where h is Planck's constant and ν is frequency.
Correct answer: Plancks Quantum theory- A. Shorter wavelength
- B. Larger wavelength
- C. X-ray not produced
- D. All are possible
Explanation: According to Moseley's relationship, increasing atomic number increases the frequency of characteristic X-rays.
Correct answer: Shorter wavelength- A. Beta-rays
- B. Alpha-rays
- C. X-rays
- D. Gamma-rays
Explanation: When high-speed electrons strike a heavy-metal target, they are suddenly decelerated and emit X-rays, including bremsstrahlung and…
Correct answer: X-rays- A. 2-times
- B. 3-times
- C. 4-times
- D. 6 times
Explanation: According to the Bohr model, the radius of an orbit is proportional to n2, so r2/r1 = 2²/1² = 4.
Correct answer: 4-times- A. In continuous manner
- B. Discontinuous manner
- C. Simultaneously
- D. In the form of heat
Explanation: Planck proposed that energy is emitted or absorbed in definite packets called quanta, so the exchange is discontinuous rather than…
Correct answer: Discontinuous manner- A. 0.33 nm
- B. 0.34 nm
- C. 0.35 nm
- D. 0.36 nm
Explanation: The de Broglie wavelength is λ = h/mv = (6.626 x 10^-34 J s)/[(9.109 x 10^-31 kg)(2.188 x 10^6 m/s)] = 3.33 x 10^-10 m.
Correct answer: 0.33 nm- A. Pauli exclusion principle
- B. Hund's rule
- C. Aufbau's principle
- D. Le-Chatelier's principle
Explanation: Aufbau is a German word meaning 'building up' and is not the name of a scientist; the Aufbau principle describes filling lower-energy…
Correct answer: Aufbau's principle- A. Arithmetical values
- B. Numerical values
- C. Leometric values
- D. Logical values
Explanation: Quantum numbers are numerical values that specify an electron's energy level, subshell, orbital orientation and spin.
Correct answer: Numerical values- A. n=2,l=1,m1=0,ms=+1/2
- B. n=2,l=1,m1=-1,ms=+1/2
- C. n=2,l=0,m1=0,ms=-1/2
- D. n=2,l=2,m1=1,ms=-1/2
Explanation: For n = 2, the azimuthal quantum number l can only be 0 or 1, so l = 2 is not allowed; option d is therefore invalid.
Correct answer: n=2,l=2,m1=1,ms=-1/2- A. e/m ratio of an electron
- B. Spin of an electron
- C. Angular momentum of an electron
- D. Magnetic momentum of an electron
Explanation: The azimuthal quantum number, l, identifies the subshell and therefore determines the electron's orbital angular momentum, whose magnitude…
Correct answer: Angular momentum of an electron- A. Size of orbitals
- B. Shape of orbitals
- C. Orientation of orbitals
- D. All of the above
Explanation: The magnetic quantum number, ml, gives the orientation of an orbital in space within a subshell.
Correct answer: Orientation of orbitals- A. n
- B. 1
- C. m
- D. s
Explanation: The principal quantum number, n, specifies the main energy level and is therefore the quantum number most directly associated with an…
Correct answer: n