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.
Last updated
922 questions · page 21 of 47
- A. 1.09678 x 10^7 m-1
- B. 1.602 x 10^-19 C
- C. 1.7588 x 10^11 C
- D. 1.007 x 10^7 m-1
Explanation: You'll have to rote learn this. Memorise the power and units.
Correct answer: 1.09678 x 10^7 m-1402. A 4s orbital has:
- A. One node
- B. Two nodes
- C. three nodes
- D. O nodes
Explanation: 4s orbital has 3 radial nodes plus 0 angular nodes
Correct answer: three nodes- A. IA group and 3rd period
- B. IIIA group and 1st period
- C. IA group and 8th period
- D. VIIA group and 3rd period
Explanation: Elements' position in the periodic table can be determined by its electronic configuration.
Correct answer: IA group and 3rd period- A. Mg2+
- B. V3+
- C. Ti3+
- D. Fe2+
Explanation: Iron ion (Fe2+) is the correct answer as it has the electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶, resulting in 4 unpaired electrons in…
Correct answer: Fe2+- A. Na+
- B. Cu+
- C. K+
- D. S2
Explanation: The following is the solution to this question:
Correct answer: Cu+- A. 4s
- B. 2p
- C. 3d
- D. 1s
Explanation: In the Aufbau principle, electrons fill the lowest energy orbitals first.
Correct answer: 3d- A. [Ne] 4s2 3d5
- B. [Ar] 4s1 3d5
- C. [Ne] 4s2 3d6
- D. [Ar] 4s2 3d4
Explanation: The correct electronic configuration of Cr (Z = 24) is [Ar] 4s1 3d5. The Aufbau principle states that electrons fill orbitals in order of…
Correct answer: [Ar] 4s1 3d5- A. Light metals
- B. Inert gases
- C. Halogens
- D. Rare earth metals
Explanation: Option B is correct as Inert gases or Noble gases have their stable electronic subshell configurations.
Correct answer: Inert gases- A. 2.43 x 10^5 cm-1
- B. 1.87 x 10^5cm-1
- C. 243 x 10^5 m-1
- D. 1.8 x 10^5 m-1
Explanation: The wave number is proportional to the square of the atomic number. So, we have the atomic number, squared, of Be as 16 and of hydrogen as…
Correct answer: 2.43 x 10^5 cm-1- A. One s and two p
- B. One s and three p
- C. One s and one p
- D. Two s and two p
Explanation: In sp hybridization, one s orbital and one p orbital hybridize to form two sp orbitals, each possessing 50% s character and 50% p…
Correct answer: One s and one p- A. Has a tightly bonded structure
- B. Has high density
- C. Has no free electrons available for conduction
- D. Is transparent to light
Explanation: Diamond is a poor electrical conductor because it lacks free electrons.
Correct answer: Has no free electrons available for conduction- A. Equal number of electrons and neutrons
- B. Equal number of electrons, protons and neutrons
- C. Number of neutrons is double than the number of protons
- D. Number of neutrons is half than the number of protons
Explanation: Tritium is the isotope of the hydrogen having mass number 3 and proton number 1.Number of neutrons are mass number-number protons which…
Correct answer: Number of neutrons is double than the number of protons- A. 4f
- B. 4s
- C. 4p
- D. 4d
Explanation: The correct order of electron orbital filling is determined by the Aufbau principle, which states that electrons fill orbitals starting…
Correct answer: 4p- A. 1.008 amu
- B. 1.009 amu
- C. 0.000550 amu
- D. 0.5500 amu
Explanation: The mass of an electron is approximately 0.000550 amu, which is much smaller compared to the masses of protons and neutrons (approximately…
Correct answer: 0.000550 amu- A. d1 system with respect to the electronic configuration.
- B. d3 system with respect to the electronic configuration.
- C. d7 system with respect to the electronic configuration.
- D. d10 system with respect to the electronic configuration.
Explanation: Copper (Cu) is an exception in electronic configurations due to the stability provided by a fully filled d-orbital and a half-filled…
Correct answer: d10 system with respect to the electronic configuration.- A. Less than zero
- B. More then zero
- C. One
- D. Infinite
Explanation: According to Heisenberg's uncertainty principle, the exact position and momentum of electron cannot be found simultaneously.
Correct answer: Infinite- A. Towards anode
- B. Towards cathode
- C. Move randomly
- D. Move towards vacuum in the tube
Explanation: In discharge tube cathode rays (a beam of negative particles) and canal rays (positive rays) moves opposite to each other.
Correct answer: Towards cathode- A. 1 x 10^-8 m
- B. 1 x 10^-1 m
- C. 1 x 10^-11 m
- D. 1 x 10^-13 m
Explanation: The first electron shell radius for hydrogen is 0.53Ao = 5.3 x10-11m. The radii for the remaining shells also range from between 10-11m to…
Correct answer: 1 x 10^-11 m- A. Electrons
- B. Protons
- C. Neutrons
- D. Positrons
Explanation: Atomic number equals the number of protons in the nucleus of an atom.
Correct answer: Protons- A. Li+
- B. O22-
- C. B3+
- D. F-
Explanation: The ionic radii of elements exhibit the same trend as the atomic radii.
Correct answer: O22-