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 12 of 47
221. The e/m value is maximum for _ gas because of the _ value of "m" for positive rays obtained from it.
- A. Oxygen gas, lowest
- B. Hydrogen gas, highest
- C. Hydrogen gas, lowest
- D. Helium gas, highest
Explanation: The elemnt with smallest mass will have the maximum e/m value.Option A: mass of oxygen gas is 32amuOption B: mass of hydrogen gas is 2amu…
Correct answer: Hydrogen gas, lowest- A. Energy level
- B. Orbital or subshell
- C. Orientation of orbital
- D. Spin
Explanation: 'n' is the Principal Quantum Number that represents the different energy levels.
Correct answer: Orientation of orbital- A. Z=2
- B. Z=3
- C. Z=4
- D. Z=5
Explanation: △E=λhc =3.055×10−8m(6.63×10−34J−s)(3.00×108m/s) =6.△EH =43 (2.=1.63×10−18J;△E=△EH (Z2=△EH △E =(1.63×10−18)(6.52×10−18) =4;Z=2(helium)
Correct answer: Z=2- A. Electron
- B. Neutron
- C. Positron
- D. Proton
Explanation: Neutrons are uncharged particles that reside in the nucleus.Electrons are negatively charged.Protons and positrons, both have a positive…
Correct answer: Neutron- A. Ionic, One
- B. Coordinate Covalent, One Lone Pair
- C. Covalent, 1 Lone Pair
- D. All of These
Explanation: In hydrogen bonding, the oxygen atom of one water molecule forms a coordinate-covalent bond with the hydrogen atom of another water…
Correct answer: Coordinate Covalent, One Lone Pair- A. Shape
- B. Energy
- C. Position
- D. All of these
Explanation: Inorder to solve this question, candidate first must know the basic definition of Quantum number and following that, he/she must know what…
Correct answer: All of these- A. Planar
- B. Axial
- C. Non directional
- D. Directional
Explanation: A p-orbital has two lobes like a dumbell and it has a strong directional character.
Correct answer: Directional- A. Oval
- B. Elliptical
- C. Cylindrical
- D. Circular
Explanation: The model states that electrons in atoms move in circular orbits around a central nucleus
Correct answer: Circular- A. 4s < 4p < 4d < 4f
- B. 4p < 4s < 4f < 4d
- C. 4s < 4f < 4p < 4d
- D. 4f < 4s < 4d < 4p
Explanation: According to the order of increasing energy, the s orbitals have lower energy than the p orbitals.
Correct answer: 4s < 4p < 4d < 4f- A. No change
- B. Absorbed
- C. Released
- D. Remains constant
Explanation: When an electron jumps from an inner to outer shell, energy is absorbed while when it jumps from outer to inner shell energy is released.
Correct answer: Released- A. [He]2s1
- B. [Ne]3s1
- C. [Ne]3s2
- D. [He]2s2
Explanation: Option B is correct since sodium11 has 11 electrons whereas Ne has 10 electrons.The [Ne] part represents the noble gas configuration of…
Correct answer: [Ne]3s1- A. Democritus
- B. Berzelius
- C. Bohr
- D. Dalton
Explanation: John Dalton (1766-1844) is the scientist credited for proposing the atomic theory.
Correct answer: Dalton- A. 1837
- B. 1839
- C. 1836
- D. 1834
Explanation: The electron's mass is approximately 1836 times smaller than that of the proton. (Fact)
Correct answer: 1836- A. It did not account for the stability of atom.
- B. It did not account for the attraction b/w protons and neutrons.
- C. The atom did not have neutrons.
- D. None of these.
Explanation: Rutherford's model proposed that the negatively charged electrons surround the nucleus of an atom.
Correct answer: It did not account for the stability of atom.- A. 2.8 × 10−18
- B. 0.545 × 10−18
- C. −2 ∙ 18 × 10−18
- D. −1312 ∙ 36
Explanation: By using the formula for the energy of an electron in the nth orbit En=-{me-4Z2/8 ε2 h2 n2} For hydrogen Z=1 and by putting values of…
Correct answer: 0.545 × 10−18- A. β, cancer
- B. α, cancer
- C. α, kidney stone
- D. β, kidney stone
Explanation: Radon emits alpha particles that are used for therapeutic purposes to treat cancer.
Correct answer: α, cancer- A. Gain electrons readily
- B. Gains electron with difficulty
- C. Lose electrons less readily
- D. Lose electrons readily
Explanation: Ionisation energy is the minimum energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or…
Correct answer: Lose electrons readily- A. Number of protons
- B. Number of electrons and protons
- C. Number of neutrons
- D. Sum of protons and neutrons
Explanation: The atomic number Z of an atom represents the number of protons in the nucleus.
Correct answer: Number of protons- A. Principal
- B. Azimuthal
- C. Magnetic
- D. Spin
Explanation: Quantum number which is not derived from Schrodinger wave equation is spin quantum number it was given by Uhlenbeck and Goudsmith.
Correct answer: Spin- A. n = 5, l = 0, m = 0, s = +1/2
- B. n = 4, l = 0, m = 0, s = -1/2
- C. n = 3, l = 1, m = 1, s = -1/2
- D. n = 5, l = 1, m = 0, s = +1/2
Explanation: Higher the n + l value higher is the energy. If the n+ l value is same then for higher energy is corresponds to the greater n value…
Correct answer: n = 5, l = 1, m = 0, s = +1/2