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 25 of 47
- A. Anode
- B. Cathode
- C. Gas molecules in the tube
- D. None of these
Explanation: Option C is correct since the electrons emitted from the 'cathode' collide with the gas atoms found in the tube, knocking one or two…
Correct answer: Gas molecules in the tube- A. Joules
- B. Joules/atom
- C. Kilojoules
- D. Kilojoules/atom
Explanation: Value of energy will be Joules/atom in this specific case
Correct answer: Joules/atom- A. Energy of electron
- B. Location of electron
- C. Shells or energy levels
- D. All of these options are correct
Explanation: The value of principal quantum number n represents no of shells or energy levels. and location too
Correct answer: All of these options are correct- A. Twice
- B. Four times
- C. Same
- D. Eight times
Explanation: In the ground state = n = 1, hydrogen has radius = r = 0.529Å. When hydrogen is in excited state = n = 2 and, as r = 0.529(n²) Å.
Correct answer: Four times- A. One yellow
- B. Two yellow
- C. Two brown
- D. Two golden
Explanation: Remember that the line spectrum of sodium contains two yellow colored lines separated by a definite distance.
Correct answer: Two yellow- A. Anode
- B. Both of these
- C. Cathode
- D. None of these
Explanation: Since the cathode is a negatively charged terminal, and opposite charges attract, positive charges would move the cathode.
Correct answer: Cathode- A. 3
- B. 2
- C. 4
- D. 5
Explanation: Calcium has an atomic number of 20, which means it has 20 electrons. There are 2 electrons in the first shell, 8 electrons in the second…
Correct answer: 4488. Which one of the following pairs has the same electronic configuration as possessed by Neon (Ne-10)?
- A. Na+, Cl-
- B. K+, Cl-
- C. Na+, K+
- D. Na+, F-
Explanation: Sodium (Na+) has the electronic configuration 1s^2 2s^2 2p^6 3s^1, while fluorine (F-) has the electronic configuration 1s^2 2s^2 2p^5.
Correct answer: Na+, F-- A. Al3+
- B. Si3+
- C. Mg2+
- D. Na1+
Explanation: Silicon has the highest atomic number and Si3+ has the highest nuclear charge. Hence, it has the smallest radius.
Correct answer: Si3+- A. N > C
- B. P > Si
- C. Ar > Cl
- D. Li > Be
Explanation: Option D is correct because Lithium (Li) and Beryllium (Be) are in the same period, with Li positioned to the left of Be.
Correct answer: Li > Be- A. [Xe]4f14, 5d10, 6s1
- B. [Xe]4f¹⁰f10, 5d¹⁰, 6s²
- C. [Xe]4f14, 5d9, 6s2
- D. [Xe]4f14, 5d10, 6s2
Explanation: Atomic number of Au is 79, its electronic configuration is1s22s22p63s23p63d104s24p64d105s25p64f145d106s1(The electronic configuration of…
Correct answer: [Xe]4f14, 5d10, 6s1- A. 3d < 4p <4s
- B. 4s < 3d < 4p
- C. 4p < 4s < 3d
- D. 4p < 3d < 4s
Explanation: The Aufbau principle states that electrons fill lower-energy atomic orbitals before filling higher-energy ones (Aufbau is German for…
Correct answer: 4s < 3d < 4p- A. Depends on the nature of gas taken in the discharge tube
- B. Depends upon the nature of cathode in discharge tube
- C. Is independent of the nature of the gas in discharge tube
- D. Depends upon the nature of anode in the discharge tube
Explanation: Cathode rays in the discharge tube are the electrons produced due to ionisation of gas and that emitted by cathode due to collision of…
Correct answer: Is independent of the nature of the gas in discharge tube- A. As-3, Ga+3, Ca
- B. As+1, Ga+2, Ca
- C. As+3, Ga+3, Ca
- D. As+1, Ga, Ca+2
Explanation: Charge on any species is equal to protons-electrons:In this case:For As, 33-30=+3For Ga: 31-28=+3For Ca: 20-20-0Hence our answer is CAs it…
Correct answer: As+3, Ga+3, Ca- A. 9.1095 x 10^-31 g
- B. 91.095 x 10^-31 g
- C. 9.1095 x 10^-28 g
- D. 0.919095 x 10^-33 g
Explanation: If e/m is equal to 1.7588x10^11 and the charge on an electron is 1.6 x10^-19 then the mass can be calculated as: 1.7588x10^11=1.6x10^-19/m…
Correct answer: 9.1095 x 10^-28 g- A. A
- B. B
- C. C
- D. D
Explanation: The suitable structure of the dot structure of the chlorine molecule is shown in option B as it shows 7 electrons in each of the chlorine…
Correct answer: B- A. v = √(2eV/m)
- B. v = √(eV/m)
- C. v = √(2mV/e)
- D. v = √(m/eV)
Explanation: Energy gained by the electron when accelerated through a potential of V volts is E=eV This energy is completely converted to kinetic…
Correct answer: v = √(2eV/m)- A. CH3
- B. CO
- C. H2O
- D. NH3
Explanation: Key points Valence shell: the larger atom has 5 electrons so it means it belongs to group VA A smaller atom has only one valence electron…
Correct answer: NH3499. The maximum number of electrons in an electronic configuration can be calculated by using formula:
- A. 2 (2l + 1)
- B. 2n2 + 2
- C. 2n2
- D. 2n2 + 1
Explanation: ( 2n^2) n=number of shells A.2(2l+1) is the formula for the number of electrons in a subshell.
Correct answer: 2n2- A. Spherical, dumb-bell
- B. Dumb-bell, spherical
- C. Spherical, double dumb-bell
- D. Spherical, spherical
Explanation: The s-orbital is spherical and the p-orbital is dumb-bell shaped.Hence, the correct option is A
Correct answer: Spherical, dumb-bell