Lesson 3.1.1.3

3.1.1.3 Electron configuration Quiz: AQA Chemistry, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.1.1.3, Electron configuration: 20 multiple choice questions for the AQA Chemistry (7405), Unit 1: Physical chemistry, written with Revision Ninja.

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The 20 questions

  1. What is the electron configuration of a neutral oxygen atom (Z = 8)?

    • 1s2 2s1 2p5
    • 1s2 2s2 2p6
    • 1s2 2s2 3p4
    • 1s2 2s2 2p4

  2. Which orbital types (sub-shells) are used in electron configurations of atoms and ions up to Z = 36?

    • p and d only
    • s, p, f and d
    • s and p only
    • s, p and d only

  3. What is the definition of first ionisation energy?

    • The energy needed to remove one electron from a single gaseous atom in a solid
    • The energy needed to remove all electrons from one mole of gaseous atoms
    • The energy needed to remove one electron from each atom in one mole of gaseous atoms
    • The energy released when one electron is added to one mole of gaseous atoms

  4. Which equation represents the first ionisation energy of sodium?

    • Na+(g) -> Na2+(g) + e-
    • Na(g) + e- -> Na-(g)
    • Na(g) -> Na+(g) + e-
    • Na(s) -> Na+(s) + e-

  5. Which equation represents the second ionisation energy of magnesium?

    • Mg(g) -> Mg2+(g) + 2e-
    • Mg(g) -> Mg+(g) + e-
    • Mg2+(g) -> Mg(g) + 2e-
    • Mg+(g) -> Mg2+(g) + e-

  6. What is the electron configuration of an iron atom (Z = 26)?

    • [Ar] 3d6 4s2
    • [Ar] 4s2 4p6
    • [Ar] 3d8
    • [Ar] 3d4 4s4

  7. What is the electron configuration of the chloride ion, Cl-?

    • 1s2 2s2 2p6 3s2 3p5
    • 1s2 2s2 2p6 3s2 3p6 4s1
    • 1s2 2s2 2p6 3s2 3p6
    • 1s2 2s2 2p6 3s2 3p4

  8. Successive ionisation energies of an element show a large jump between the 2nd and 3rd values. Which group is the element in?

    • Group 4
    • Group 3
    • Group 1
    • Group 2

  9. Why is the first ionisation energy of aluminium lower than that of magnesium?

    • Al has one fewer shell than Mg, so its outer electron sits closer to the nucleus and is held tightly
    • Al's outer electron is in a 3p sub-shell, which is higher in energy than 3s, so it is easier to remove
    • Al has fewer protons than Mg, so the nuclear attraction on the outer electron is much weaker overall
    • Al's outer electrons form a complete shell, which makes them more strongly held and harder to remove

  10. What is the electron configuration of a Ti2+ ion (Z = 22)?

    • [Ar] 3d4
    • [Ar] 3d1 4s1
    • [Ar] 4s2
    • [Ar] 3d2

  11. How many electrons are in the 3p sub-shell of a neutral sulfur atom?

    • 8
    • 6
    • 2
    • 4

  12. Which element has the electron configuration 1s2 2s2 2p6 3s2 3p3?

    • Phosphorus
    • Silicon
    • Nitrogen
    • Sulfur

  13. Which ion has the same electron configuration as neon?

    • Na+
    • Mg
    • Cl
    • K+

  14. How many electrons are in the 2p sub-shell of a neutral neon atom?

    • 4
    • 6
    • 10
    • 2

  15. Successive ionisation energies for an element are 578, 1817, 2745 and 11578 kJ mol-1. Which group is the element in?

    • Group 3
    • Group 2
    • Group 1
    • Group 4

  16. Why is the first ionisation energy of oxygen lower than that of nitrogen?

    • Oxygen has fewer neutrons than nitrogen, so the shielding of its outer electrons by the nucleus is noticeably less effective overall
    • Oxygen's removed electron comes from a 2p orbital that already holds a paired electron, so repulsion lowers the energy needed
    • Oxygen has one more shell than nitrogen, so its outer electrons are further from the nucleus and easier to lose completely
    • Oxygen has no electrons in 2p orbitals, so its first electron must be removed from a lower energy sub-shell instead

  17. Why is the first ionisation energy of boron lower than that of beryllium?

    • Boron has fewer protons than beryllium, so the nuclear attraction on its outer electron is much weaker overall
    • Boron has one more neutron than beryllium, so its extra shielding of the outer electron makes removal easier
    • Boron's outer electron is in a 2p sub-shell, which is higher in energy than 2s, so it is easier to remove
    • Boron's outer electron is in a full 2s sub-shell, so it is more strongly held and harder to remove overall

  18. Which statement about successive ionisation energies is correct?

    • Each successive ionisation energy is larger than the previous one, because the ion becomes more positive
    • The second ionisation energy is always equal to the first
    • Each successive ionisation energy is smaller than the previous one, because ions shield more
    • Successive ionisation energies are equal for all elements

  19. Which element in Period 3 has the largest first ionisation energy?

    • Silicon
    • Chlorine
    • Sodium
    • Argon

  20. Which electron configuration is correct for a neutral copper atom (Z = 29)?

    • [Ar] 3d8 4s3
    • [Ar] 4s2 3d9 4p1
    • [Ar] 3d10 4s1
    • [Ar] 3d9 4s2

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