The nucleus
5.1.2What the syllabus asks of you
- Describe the composition of the nucleus in terms of protons and neutrons
- Describe how atoms form positive ions by losing electrons or negative ions by gaining electrons
- Define the terms proton number (atomic number) Z and nucleon number (mass number) A and be able to calculate the number of neutrons in a nucleus
- Explain the term nuclide and use the nuclide notation A ZX
- Explain what is meant by an isotope and state that an element may have more than one isotope
Read the notes first
Chapter 5: The nucleus
Drill this topic
Every question on The nucleus, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
23 questions
1May / June 2026 · Paper 12 · Q36Show mark scheme →
A2 protons, 2 neutrons, 3 electrons, neutral
B4 protons, 3 neutrons, 3 electrons, neutral
C6 protons, 5 neutrons, 5 electrons, positive
D6 protons, 7 neutrons, 6 electrons, negative
Mark scheme
2May / June 2025 · Paper 11 · Q35Show mark scheme →
A1 and 2
B1 and 4
C2 and 3
D3 and 4
Mark scheme
3Oct / Nov 2024 · Paper 11 · Q38Show mark scheme →
AZ
BR
CZ + R
D2Z + R
Mark scheme
4Oct / Nov 2024 · Paper 12 · Q36Show mark scheme →
AR is the nucleon number which is different for different isotopes of X.
BR is the proton number which is the same for different isotopes of X.
CZ is the nucleon number which is the same for different isotopes of X.
DZ is the proton number which is different for different isotopes of X.
Mark scheme
5May / June 2024 · Paper 12 · Q38Show mark scheme →
A1 and 2
B1 and 4
C2 and 4
D3 and 4
Mark scheme
6Oct / Nov 2023 · Paper 11 · Q35Show mark scheme →
Aneutrons and electrons only
Bprotons and electrons only
Cprotons and neutrons only
Dprotons, neutrons and electrons
Mark scheme
7May / June 2023 · Paper 11 · Q35Show mark scheme →
Adifferent / different
Bdifferent / same
Csame / different
Dsame / same
Mark scheme
8May / June 2023 · Paper 12 · Q34Show mark scheme →
A27 protons, 32 neutrons
B27 protons, 59 neutrons
C59 protons, 27 neutrons
D59 protons, 32 neutrons
Mark scheme
9May / June 2023 · Paper 12 · Q35Show mark scheme →
A39
B79
C118
D197
Mark scheme
10Oct / Nov 2021 · Paper 12 · Q40Show mark scheme →
Adifferent / different
Bdifferent / same
Csame / different
Dsame / same
Mark scheme
11May / June 2021 · Paper 11 · Q40Show mark scheme →
Aneutrons and electrons
Belectrons and protons
Cneutrons only
Dneutrons and protons
Mark scheme
12Oct / Nov 2020 · Paper 12 · Q40Show mark scheme →
A4 neutrons, 5 protons, 4 electrons
B4 neutrons, 5 protons, 5 electrons
C5 neutrons, 4 protons, 5 electrons
D5 neutrons, 5 protons, 4 electrons
Mark scheme
13May / June 2020 · Paper 11 · Q37Show mark scheme →
AA
BA – Z
CZ – A
DZ
Mark scheme
14May / June 2019 · Paper 11 · Q40Show mark scheme →
A1
B5
C6
D11
Mark scheme
15Oct / Nov 2018 · Paper 11 · Q37Show mark scheme →
Aa helium atom and a neutron
Ba helium atom and a proton
Ca helium nucleus and a neutron
Da helium nucleus and a proton
Mark scheme
16Oct / Nov 2018 · Paper 11 · Q40Show mark scheme →
A235 nucleons, 143 neutrons
B237 nucleons, 147 neutrons
C238 nucleons, 144 neutrons
D241 nucleons, 146 neutrons
Mark scheme
17Oct / Nov 2018 · Paper 12 · Q40Show mark scheme →
ABoth isotopes have the same number of electrons in a nucleus.
BBoth isotopes have the same number of protons in a nucleus.
CBoth isotopes have the same number of neutrons in a nucleus.
DBoth isotopes have the same number of nucleons in a nucleus.
Mark scheme
18May / June 2018 · Paper 11 · Q40Show mark scheme →
A90 protons, 140 neutrons
B91 protons, 138 neutrons
C92 protons, 139 neutrons
D93 protons, 136 neutrons
Mark scheme
19May / June 2018 · Paper 12 · Q40Also set in May / June 2018 Paper 11Show mark scheme →
A36
B48
C84
D120
Mark scheme
20Oct / Nov 2017 · Paper 11 · Q39Show mark scheme →
AIt contains one more neutron and one more electron.
BIt contains one more proton and one more electron.
CIt contains two more neutrons.
DIt contains two more protons.
Mark scheme
21Oct / Nov 2016 · Paper 11 · Q40Show mark scheme →
Athe number of electrons in the atom
Bthe number of neutrons in the atom
Cthe number of nucleons in the atom
Dthe number of particles in the atom
Mark scheme
22May / June 2016 · Paper 11 · Q40Show mark scheme →
AThe nucleus contains 7 neutrons and 8 protons.
BThe nucleus contains 7 neutrons and 15 protons.
CThe nucleus contains 7 protons and 8 neutrons.
DThe nucleus contains 7 protons and 15 neutrons.
Mark scheme
23May / June 2016 · Paper 12 · Q40Show mark scheme →
AP and Q only
BP and R only
CQ and R only
DP, Q and R
Mark scheme