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Electron structure: OCR A‑Level Chemistry A questions

Every OCR A-Level Chemistry A exam question on 2.2.1 Electron structure, 2016–2025, with its mark scheme and examiner’s report.

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1,820 questions

  1. Q2

    June 2025 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2025 AS Paper 1, question 2: How many p electrons does an atom of chlorine have? A 5 B 7 C 11 D 17 Your answer [1]

  2. Q1

    June 2024 · Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2024 Paper 1, question 1: Oxygen has the electron configuration 1s22s22p4. 1 How are the electrons in an atom of oxygen arranged in the p-orbitals? A ↑↑ ↑↑ B ↑↓ ↑↓ C ↑↑ ↑ ↑ D ↑↓ ↑ ↑ Your

  3. Q22(a)

    June 2024 · Paper 1

    2 marks2.2.1 Electron structure5.3.1 Transition elements
    The whole paper ↗
    June 2024 Paper 1, question 22(a): Iron is in the d block of the periodic table and contains s, p and d orbitals. • Draw diagrams to show the shapes of an s orbital and a p orbital. Complete the

  4. Q1

    June 2024 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2024 AS Paper 1, question 1: Which diagram shows a p‑orbital? A B C D Your answer [1]

  5. Q2(a)(i)

    June 2024 · AS Paper 2

    3 marks2.2.1 Electron structure
    The whole paper ↗
    June 2024 AS Paper 2, question 2(a)(i): Complete the table below with the electron configurations and blocks. Group 2 Group 17 (7) Period 2 Be F 1s2 1s2 Period 3 Mg Cl 1s2 1s2 Block [3]

  6. Q4

    June 2023 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2023 AS Paper 1, question 4: How many p-orbitals are occupied by electrons in a sulfur atom? A 2 B 4 C 6 D 10 Your answer [1]

  7. Q1(a)(ii)

    June 2023 · AS Paper 2

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2023 AS Paper 2, question 1(a)(ii): Complete the electron configuration of a titanium atom. 1s2 [1]

  8. Q4

    June 2022 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2022 AS Paper 1, question 4: What is the number of paired orbitals in a sulfur atom? A 4 B 6 C 7 D 8 Your answer [1]

  9. Q22(b)

    June 2022 · AS Paper 1

    2 marks2.1.1 Atomic structure and isotopes2.2.1 Electron structure
    The whole paper ↗
    June 2022 AS Paper 1, question 22(b): Complete the table for an atom and an ion of two different elements. Mass Element Protons Neutrons Electron configuration Charge number 28 34 0 1s22s22p63s23p6

  10. Q16(b)(iii)

    November 2021 · Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2021 Paper 1, question 16(b)(iii): Electrons occupy orbitals. In Table 16.2 below, add a tick (✓) below the ionisation numbers that are responsible for removing an electron from a full orbital in

  11. Q9

    November 2021 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2021 AS Paper 1, question 9: Which element has atoms with the largest number of unpaired p-electrons? A aluminium B oxygen C chlorine D phosphorus Your answer [1]

  12. Q21(a)

    November 2021 · AS Paper 1

    2 marks2.2.1 Electron structure
    The whole paper ↗
    November 2021 AS Paper 1, question 21(a): Complete the table to show the maximum number of electrons that can occupy each shell and sub-shell. Some boxes may need to be left blank. Sub-shell Total numbe

  13. Q5(d)(ii)

    November 2021 · AS Paper 2

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2021 AS Paper 2, question 5(d)(ii): Complete the electron configuration of gallium. 1s2 [1]

  14. Q5

    November 2020 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2020 AS Paper 1, question 5: Which p-block element contains atoms with one unpaired electron? A Al B Si C P D S Your answer [1]

  15. Q21(a)

    November 2020 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2020 AS Paper 1, question 21(a): Complete the table to show the number of electrons that can fill the first four shells. Shell 1st shell 2nd shell 3rd shell 4th shell Number of electrons [1]

  16. Q22(a)(i)

    November 2020 · AS Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    November 2020 AS Paper 1, question 22(a)(i): Complete the electron configuration of a bromine atom. 1s2 [1]

  17. Q1

    June 2019 · Paper 1

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2019 Paper 1, question 1: In the diagrams below, each box represents an orbital and each electron is shown as an arrow. Which diagram shows the correct arrangement of electrons in an ato

  18. Q21(c)

    June 2019 · AS Paper 1

    2 marks2.2.1 Electron structure
    The whole paper ↗
    June 2019 AS Paper 1, question 21(c): Electrons occupy orbitals which are arranged in energy levels. In the diagram below, each box represents an orbital and each electron is shown as an arrow. Labe

  19. Q1(a)(i)

    June 2018 · Paper 3

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2018 Paper 3, question 1(a)(i): The element that forms a 1– ion with the same electron configuration as helium. [1]

  20. Q2(c)(i)

    June 2018 · AS Paper 2

    1 mark2.2.1 Electron structure
    The whole paper ↗
    June 2018 AS Paper 2, question 2(c)(i): Complete the full electron configuration of a selenium atom. 1s2 [1]
All 25 questions on Electron structure, as a list
  1. June 2025, AS Paper 1, Q2 (1 mark): How many p electrons does an atom of chlorine have? A 5 B 7 C 11 D 17 Your answer [1]
  2. June 2024, Paper 1, Q1 (1 mark): Oxygen has the electron configuration 1s22s22p4. 1 How are the electrons in an atom of oxygen arranged in the p-orbitals? A ↑↑ ↑↑ B ↑↓ ↑↓ C ↑↑ ↑ ↑ D ↑↓ ↑ ↑ Your
  3. June 2024, Paper 1, Q22(a) (2 marks): Iron is in the d block of the periodic table and contains s, p and d orbitals. • Draw diagrams to show the shapes of an s orbital and a p orbital. Complete the
  4. June 2024, AS Paper 1, Q1 (1 mark): Which diagram shows a p‑orbital? A B C D Your answer [1]
  5. June 2024, AS Paper 2, Q2(a)(i) (3 marks): Complete the table below with the electron configurations and blocks. Group 2 Group 17 (7) Period 2 Be F 1s2 1s2 Period 3 Mg Cl 1s2 1s2 Block [3]
  6. June 2023, AS Paper 1, Q4 (1 mark): How many p-orbitals are occupied by electrons in a sulfur atom? A 2 B 4 C 6 D 10 Your answer [1]
  7. June 2023, AS Paper 2, Q1(a)(ii) (1 mark): Complete the electron configuration of a titanium atom. 1s2 [1]
  8. June 2022, AS Paper 1, Q4 (1 mark): What is the number of paired orbitals in a sulfur atom? A 4 B 6 C 7 D 8 Your answer [1]
  9. June 2022, AS Paper 1, Q22(b) (2 marks): Complete the table for an atom and an ion of two different elements. Mass Element Protons Neutrons Electron configuration Charge number 28 34 0 1s22s22p63s23p6
  10. November 2021, Paper 1, Q16(b)(iii) (1 mark): Electrons occupy orbitals. In Table 16.2 below, add a tick (✓) below the ionisation numbers that are responsible for removing an electron from a full orbital in
  11. November 2021, AS Paper 1, Q9 (1 mark): Which element has atoms with the largest number of unpaired p-electrons? A aluminium B oxygen C chlorine D phosphorus Your answer [1]
  12. November 2021, AS Paper 1, Q21(a) (2 marks): Complete the table to show the maximum number of electrons that can occupy each shell and sub-shell. Some boxes may need to be left blank. Sub-shell Total numbe
  13. November 2021, AS Paper 2, Q5(d)(ii) (1 mark): Complete the electron configuration of gallium. 1s2 [1]
  14. November 2020, AS Paper 1, Q5 (1 mark): Which p-block element contains atoms with one unpaired electron? A Al B Si C P D S Your answer [1]
  15. November 2020, AS Paper 1, Q21(a) (1 mark): Complete the table to show the number of electrons that can fill the first four shells. Shell 1st shell 2nd shell 3rd shell 4th shell Number of electrons [1]
  16. November 2020, AS Paper 1, Q22(a)(i) (1 mark): Complete the electron configuration of a bromine atom. 1s2 [1]
  17. June 2019, Paper 1, Q1 (1 mark): In the diagrams below, each box represents an orbital and each electron is shown as an arrow. Which diagram shows the correct arrangement of electrons in an ato
  18. June 2019, AS Paper 1, Q21(c) (2 marks): Electrons occupy orbitals which are arranged in energy levels. In the diagram below, each box represents an orbital and each electron is shown as an arrow. Labe
  19. June 2018, Paper 3, Q1(a)(i) (1 mark): The element that forms a 1– ion with the same electron configuration as helium. [1]
  20. June 2018, AS Paper 2, Q2(c)(i) (1 mark): Complete the full electron configuration of a selenium atom. 1s2 [1]
  21. June 2017, AS Paper 1, Q6 (1 mark): Which element has atoms with the greatest number of singly occupied orbitals? A C B Cl C Ca D Ga Your answer [1]
  22. June 2017, AS Paper 2, Q1(c)(i) (1 mark): Complete the electron configuration of a nitride ion. 1s2 [1]
  23. June 2016, AS Paper 1, Q6 (1 mark): How many orbitals are occupied in a silicon atom? A 5 B 7 C 8 D 9 Your answer [1]
  24. June 2016, AS Paper 1, Q23(a)(i) (1 mark): Write the electron configuration of a bromide ion, in terms of sub-shells. [1]
  25. June 2016, AS Paper 2, Q1(a)(i) (1 mark): Write the electron configuration, in terms of sub-shells, of a magnesium atom. [1]

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