Isotopes: past paper questions
Real questions on isotopes
The newest 20 of 48 written questions. Open one to see it on the real paper.
- 0971/42 · October/November 2025 · Q2b[2]
Table 2.1 shows four different isotopes of iron, A, B, C and D. B C D 54 Fe 56 Fe 57 Fe 58 Fe Explain why A, B, C and D are isotopes of iron. A Table 2.1
See it on the paper → - 0971/31 · May/June 2025 · Q3a(ii)[3]
S 1 6 3 6 S 1 6 Fig. 3.1 Complete Table 3.1 to show the number of protons, neutrons and electrons in one atom of these isotopes. Table 3.1 protons neutrons electrons 3 3 S 1 6 3 6 S 1 6 Two isotopes of sulfur are shown in Fig. 3.1. (ii)
See it on the paper → - 0971/32 · May/June 2025 · Q3a(ii)[3]
Two isotopes of phosphorus are shown in Fig. 3.1. 32 15 P Fig. 3.1 Complete Table 3.1 to show the number of protons, neutrons and electrons in one atom of these isotopes. Table 3.1 neutrons electrons 31 15 P 32 15 P protons 31 15 P (ii)
See it on the paper → - 0971/41 · May/June 2025 · Q2b(i)[3]
Complete Table 2.2 to show the number of electrons, neutrons and protons in one atom or ion of these isotopes. Table 2.2 isotope electrons neutrons protons 39 19 K 41 + 19 K
See it on the paper → - 0971/41 · May/June 2025 · Q2b(ii)[2]
Table 2.3 shows the relative masses and the percentage abundances of the two isotopes in a sample of potassium. Table 2.3 relative mass of isotope percentage abundance of isotope 39 90 41 10 Calculate the relative atomic mass of this sample of potassium to one decimal place. (ii)
See it on the paper → - 0971/41 · May/June 2025 · Q2b(iii)[1]
An isotope of aluminium has a nucleon number of 27. Aluminium has a relative atomic mass of 27. State what conclusion can be made from this information.
See it on the paper → - 0971/42 · May/June 2025 · Q5d(i)[1]
State the term given to these naturally occurring atoms of rubidium.
See it on the paper → - 0971/42 · May/June 2025 · Q5d(ii)[3]
Complete Table 5.1 to show the number of protons, neutrons and electrons in the atom and ion of rubidium shown. Table 5.1 85 Rb 87 Rb + protons neutrons electrons
See it on the paper → - 0971/32 · October/November 2024 · Q6b(i)[3]
Complete Table 6.1 to show the number of electrons, neutrons and protons in the sodium atom and silver ion shown. Table 6.1 number of electrons 23 11 Na 109 + 47 Ag number of neutrons number of protons 11 62
See it on the paper → - 0971/42 · May/June 2024 · Q5a(i)[2]
Complete Table 5.1 to show the number of protons and neutrons in one atom of each isotope of sulfur. Table 5.1 32 S 34 S protons neutrons
See it on the paper → - 0971/42 · May/June 2024 · Q5a(ii)[1]
State why these isotopes have identical chemical properties.
See it on the paper → - 0971/42 · May/June 2024 · Q5a(v)[2]
Table 5.2 shows the relative abundance of these isotopes of sulfur in the sample. Table 5.2 atom 32 S 34 S relative abundance 95% 5% Calculate the relative atomic mass of sulfur in this sample to one decimal place. relative atomic mass =
See it on the paper → - 0971/42 · May/June 2024 · Q5d(ii)[2]
State the colour change when this reaction happens. . from to
See it on the paper → - 0971/31 · May/June 2023 · Q4a[2]
Sulfur has several isotopes. Define the term isotopes.
See it on the paper → - 0971/31 · May/June 2023 · Q4b[3]
Deduce the number of protons, neutrons and electrons in the sulfide ion shown. 36 2– 16 S number of protons number of neutrons number of electrons
See it on the paper → - 0971/41 · May/June 2023 · Q2b(i)[2]
State the meaning of the term isotopes.
See it on the paper → - 0971/41 · May/June 2023 · Q2b(ii)[2]
Table 2.1 shows the relative masses and the percentage abundances of the two isotopes of boron. Table 2.1 relative mass of isotope percentage abundance of isotope 10 20 11 80 Calculate the relative atomic mass of boron to one decimal place. relative atomic mass = [Total: 10]
See it on the paper → - 0971/42 · May/June 2023 · Q2d(i)[1]
State the term given to the numbers 79 and 81 in these isotopes of bromine.
See it on the paper → - 0971/42 · May/June 2023 · Q2d(ii)[3]
Complete Table 2.2 to show the number of protons, neutrons and electrons in the atom and ion of bromine shown. Table 2.2 79 Br 81 Br – protons neutrons electrons
See it on the paper → - 0971/42 · May/June 2023 · Q2d(iii)[2]
Table 2.3 shows the relative abundances of the two naturally occurring isotopes of bromine. Table 2.3 isotope 79 Br relative abundance 55% 81 Br 45% Calculate the relative atomic mass of bromine to one decimal place. relative atomic mass =
See it on the paper →
What examiners said
This question was well answered with many candidates gaining full credit. A small number confused neutrons with nucleons.
— Examiner report, May/June 2025, 0971/31 Q3(a)(ii) (Cambridge)
This was answered extremely well. The most common errors were 19 or 20 electrons for the ion and/or 18 protons for the ion.
— Examiner report, May/June 2025, 0971/41 Q2(b)(i) (Cambridge)
This was answered correctly by the vast majority of candidates.
— Examiner report, May/June 2025, 0971/41 Q2(b)(ii) (Cambridge)
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