0654.C2.2.04 — Define mass number / nucleon number as the total number of protons and neutrons in the nucleus of an atom: past paper questions
Real questions on 0654.c2.2.04 — define mass number / nucleon number as the total number of protons and neutrons in the nucleus of an atom
The newest 5 of 5 written questions. Open one to see it on the real paper.
- 0973/32 · May/June 2025 · Q7a(ii)[1]
Deduce the number of neutrons in this atom. number of neutrons =
See it on the paper → - 0973/31 · October/November 2022 · Q8a(ii)[1]
State the number of neutrons in this copper atom.
See it on the paper → - 0973/31 · May/June 2022 · Q11a(iii)[2]
The proton number of a potassium atom is 19. The nucleon number of this potassium atom is 39. State the numbers of electrons and neutrons in this potassium atom. electrons neutrons
See it on the paper → - 0973/31 · October/November 2021 · Q5a(ii)[1]
An atom of iron has a proton number of 26 and a nucleon number of 56. State the number of electrons in this atom. number of electrons
See it on the paper → - 0973/42 · May/June 2021 · Q11b(ii)[1]
State which atom has a nucleon number (mass number) of 6.
See it on the paper →
What examiners said
The majority of candidates gave the correct answer. Some incorrectly used 29 or 64.
— Examiner report, May/June 2025, 0973/32 Q7(a)(ii) (Cambridge)
The correct numbers were 19 electrons and 20 neutrons. These were the most common numbers suggested, although few candidates gained both marks.
— Examiner report, May/June 2022, 0973/31 Q11(a)(iii) (Cambridge)
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