Electrons, energy levels and atomic orbitals: past paper questions
Real questions on electrons, energy levels and atomic orbitals
The newest 20 of 52 written questions. Open one to see it on the real paper.
- 9701/41 · May/June 2026 · Q5b[1]
Complete the electronic configurations of a Co atom and a Co 2+ ion. Co atom: [Ar] Co 2+ ion: [Ar]
See it on the paper → - 9701/21 · October/November 2025 · Q1b(i)[1]
Complete the full electronic configuration of chromium. 3d 5 4s 1 (i)
See it on the paper → - 9701/21 · October/November 2025 · Q1b(ii)[1]
Deduce the total number of unpaired electrons in an atom of chromium.
See it on the paper → - 9701/22 · October/November 2025 · Q1b(ii)[1]
Deduce the total number of unpaired electrons in an atom of manganese.
See it on the paper → - 9701/23 · October/November 2025 · Q1c(ii)[1]
The oxidation state of the carbon atom in methanal is 0. Calculate the oxidation state of carbon in carbon dioxide.
See it on the paper → - 9701/42 · October/November 2025 · Q4b[1]
Define first electron affinity, EA.
See it on the paper → - 9701/42 · October/November 2025 · Q4c[2]
Explain why the first electron affinity of chlorine is more exothermic than the first electron affinity of iodine.
See it on the paper → - 9701/42 · October/November 2025 · Q5a(i)[1]
Complete the electronic configurations of a Co 2+ ion and a Co 3+ ion. Co 2+ = [Ar] 3+
See it on the paper → - 9701/42 · October/November 2025 · Q5a(ii)[1]
Explain why transition elements can form complex ions.
See it on the paper → - 9701/21 · May/June 2025 · Q2c[1]
Deduce the number of pairs of electrons in the shell with principal quantum number n = 3 in an Fe atom. number of pairs of electrons
See it on the paper → - 9701/22 · May/June 2025 · Q2b[1]
Deduce the number of pairs of electrons in the 3d sub‑shell in an iron( II ) ion.
See it on the paper → - 9701/23 · May/June 2025 · Q1a(i)[1]
Give the full electronic configuration of a fluorine atom.
See it on the paper → - 9701/23 · May/June 2025 · Q1a(ii)[1]
Deduce the number of pairs of electrons in the second energy shell, n = 2, of an oxygen atom.
See it on the paper → - 9701/23 · May/June 2025 · Q1b(iii)[4]
Arrange the three species F – , Ne and Na + in order of increasing radius. Explain your answer. < < smallest radius largest radius
See it on the paper → - 9701/21 · October/November 2023 · Q1b(i)[1]
Give the full electronic configuration of P 3– . (i)
See it on the paper → - 9701/22 · October/November 2023 · Q3a(i)[1]
Write an equation for each step. step step
See it on the paper → - 9701/23 · October/November 2023 · Q1a(i)[2]
Complete Table 1.1 to show the number of electrons in the 3p subshell and the total number of unpaired electrons in an atom of P, S and Cl .
See it on the paper → - 9701/23 · October/November 2023 · Q1b(i)[1]
Give the full electronic configuration of P 3– . (i)
See it on the paper → - 9701/21 · May/June 2023 · Q1a[3]
Complete Table 1.1. Table 1.1 number of neutrons nucleon number number of electrons 130 Te
See it on the paper → - 9701/21 · May/June 2023 · Q1b[1]
Identify the sub-shell in an atom of Te that contains electrons with the lowest energy.
See it on the paper →
What examiners said
The full electronic configuration of the P3─ ion was well answered as: 1s2 2s2 2p6 3s2 3p6.
— Examiner report, October/November 2023, 9701/21 Q1(b)(i) (Cambridge)
Most candidates were able to complete the table to show the number of electrons in the 3p subshells of P, S and Cl, as 3, 4 and 5 respectively. The total number of unpaired electrons in these elements proved challenging for some candidates, Common incorrect answers were 1, 0 and 1 respectively.
— Examiner report, October/November 2023, 9701/23 Q1(a)(i) (Cambridge)
The full electronic configuration of the P3─ ion was well answered as: 1s2 2s2 2p6 3s2 3p6.
— Examiner report, October/November 2023, 9701/23 Q1(b)(i) (Cambridge)
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