Fundamental particles
11.2What the syllabus asks of you
- understand that a quark is a fundamental particle and that there are six flavours (types) of quark: up, down, strange, charm, top and bottom
- recall and use the charge of each flavour of quark and understand that its respective antiquark has the opposite charge (no knowledge of any other properties of quarks is required)
- recall that protons and neutrons are not fundamental particles and describe protons and neutrons in terms of their quark composition
- understand that a hadron may be either a baryon (consisting of three quarks) or a meson (consisting of one quark and one antiquark)
- describe the changes to quark composition that take place during β– and β+ decay
- recall that electrons and neutrinos are fundamental particles called leptons
Read the notes first
Chapter 11: Fundamental particles
Drill this topic
Every question on Fundamental particles, untimed, marked as you go.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
87 questions
1May / June 2026 · Paper 11 · Q40Show mark scheme →
Acharm and antiup
Bdown and antitop
Cstrange and antibottom
Dup and antistrange
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2May / June 2026 · Paper 12 · Q39Show mark scheme →
Aneutrino
Bproton
Cstrange antiquark
Dup quark
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3May / June 2026 · Paper 13 · Q38Show mark scheme →
Aelectron
Bneutrino
Cneutron
Dpositron
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4May / June 2026 · Paper 14 · Q39Show mark scheme →
A^{11}_{5}B
B^{11}_{7}N
C^{12}_{6}C
D^{10}_{6}C
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5Oct / Nov 2025 · Paper 11 · Q40Show mark scheme →
Ameson
Bpositron
Cproton
Dquark
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6Oct / Nov 2025 · Paper 12 · Q38Show mark scheme →
A\frac{1}{3}e
B\frac{2}{3}e
Ce
Dzero
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7Oct / Nov 2025 · Paper 13 · Q40Show mark scheme →
Ameson
Bpositron
Cproton
Dquark
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8Oct / Nov 2025 · Paper 14 · Q40Show mark scheme →
Adown, strange, strange
Bup, charm, strange
Cup, charm, top
Dup, down, strange
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9May / June 2025 · Paper 11 · Q38Show mark scheme →
Aantineutrinos, baryons, neutrons, electrons
Bmesons, electrons, neutrinos, protons
Cpositrons, quarks, hadrons, protons
Dquarks, positrons, neutrinos, leptons
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10May / June 2025 · Paper 11 · Q40Show mark scheme →
A0e
B+1e
C+2e
D+3e
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11May / June 2025 · Paper 12 · Q39Show mark scheme →
A1 quark and 1 antiquark
B1 quark and 2 antiquarks
C2 quarks and 1 antiquark
D3 quarks
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12May / June 2025 · Paper 12 · Q40Show mark scheme →
Aup quarks 15, down quarks 18
Bup quarks 16, down quarks 17
Cup quarks 17, down quarks 16
Dup quarks 18, down quarks 15
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13May / June 2025 · Paper 13 · Q39Show mark scheme →
Aantidown quark: +1/3 e; antistrange quark: +1/3 e
Bantidown quark: +1/3 e; antistrange quark: −1/3 e
Cantidown quark: −1/3 e; antistrange quark: +1/3 e
Dantidown quark: −1/3 e; antistrange quark: −1/3 e
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14May / June 2025 · Paper 14 · Q39Show mark scheme →
Aelectron
Bneutrino
Cneutron
Dpositron
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15May / June 2025 · Paper 14 · Q40Show mark scheme →
A3
B4
C5
D6
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16Feb / March 2025 · Paper 12 · Q37Show mark scheme →
AIt consists of three quarks that must all be the same flavour.
BIt consists of three quarks that do not need to be the same flavour.
CIt consists of two quarks that must both be the same flavour.
DIt consists of two quarks that do not need to be the same flavour.
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17Feb / March 2025 · Paper 12 · Q39Show mark scheme →
Adown to antiup
Bdown to up
Cup to antidown
Dup to down
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18Feb / March 2025 · Paper 12 · Q40Show mark scheme →
A−2/3 e
B−1/3 e
C+1/3 e
D+2/3 e
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19Oct / Nov 2024 · Paper 11 · Q38Show mark scheme →
Acharm quark
Belectron
Cneutrino
Dneutron
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20Oct / Nov 2024 · Paper 11 · Q40Show mark scheme →
AA baryon is a hadron and consists of 2 quarks.
BA meson is a hadron and consists of 3 quarks.
CAn electron is a fundamental particle and is a lepton.
DA neutrino is a fundamental particle and is a hadron.
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21Oct / Nov 2024 · Paper 12 · Q38Show mark scheme →
Acharm
Bmeson
Cstrange
Dup
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22Oct / Nov 2024 · Paper 12 · Q39Show mark scheme →
A2
B3
C4
D5
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23Oct / Nov 2024 · Paper 13 · Q39Show mark scheme →
Ahadrons; hadrons
Bhadrons; leptons
Cleptons; hadrons
Dleptons; leptons
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24May / June 2024 · Paper 11 · Q39Show mark scheme →
Aelectron
Bneutrino
Cneutron
Dtop quark
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25May / June 2024 · Paper 11 · Q40Show mark scheme →
A$-\dfrac{2}{3}e$
B$-\dfrac{1}{3}e$
C$+\dfrac{1}{3}e$
D$+\dfrac{2}{3}e$
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26May / June 2024 · Paper 12 · Q38Show mark scheme →
Aleptons
Bnucleons
Cphotons
Dquarks
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27May / June 2024 · Paper 13 · Q39Show mark scheme →
Ad d s
Bs d s
Cs u s
Du u s
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28May / June 2024 · Paper 13 · Q40Show mark scheme →
Aantiquark
Bbaryon
Clepton
Dmeson
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29Feb / March 2024 · Paper 12 · Q38Show mark scheme →
Acharm ✓, strange ✗, top ✓, bottom ✗
Bcharm ✓, strange ✗, top ✗, bottom ✗
Ccharm ✗, strange ✓, top ✓, bottom ✓
Dcharm ✗, strange ✓, top ✗, bottom ✓
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30Feb / March 2024 · Paper 12 · Q40Show mark scheme →
Aproton to neutron; down becomes up
Bproton to neutron; up becomes down
Cneutron to proton; down becomes up
Dneutron to proton; up becomes down
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31Oct / Nov 2023 · Paper 11 · Q40Show mark scheme →
Adown, down, strange
Bup, down, strange
Cup, up, down
Dup, up, strange
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32Oct / Nov 2023 · Paper 12 · Q40Show mark scheme →
Au u u
Bu u d
Cu d d
Dd d d
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33Oct / Nov 2023 · Paper 13 · Q40Show mark scheme →
Aup, down, down
Bup, strange, strange
Cup, up, down
Dup, up, up
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34May / June 2023 · Paper 11 · Q40Show mark scheme →
AA proton is a baryon but not a meson.
BA proton is a meson but not a hadron.
CA proton is both a hadron and a meson.
DA proton is both a meson and a baryon.
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35May / June 2023 · Paper 12 · Q40Show mark scheme →
Aanti-down
Banti-up
Cbottom
Dcharm
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36May / June 2023 · Paper 13 · Q40Show mark scheme →
A4 up, 5 down
B5 up, 4 down
C5 up, 7 down
D7 up, 5 down
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37Feb / March 2023 · Paper 12 · Q40Show mark scheme →
A-\frac{2}{3}e
B-\frac{1}{3}e
C+\frac{1}{3}e
D+\frac{2}{3}e
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38Oct / Nov 2022 · Paper 11 · Q40Show mark scheme →
Aantineutrino, beta, meson
Bbaryon, neutrino, positron
Celectron, neutrino, alpha
Dlepton, quark, positron
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39Oct / Nov 2022 · Paper 12 · Q40Show mark scheme →
Ameson
Bpositron
Cproton
Dquark
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40Oct / Nov 2022 · Paper 13 · Q40Show mark scheme →
A–2e
B–e
C+e
D+2e
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41May / June 2022 · Paper 11 · Q40Show mark scheme →
Ahadrons 9, baryons 4, mesons 5
Bhadrons 9, baryons 5, mesons 4
Chadrons 9, baryons 9, mesons 0
Dhadrons 13, baryons 9, mesons 0
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42May / June 2022 · Paper 12 · Q40Show mark scheme →
Ad → u + β⁻ + νe
Bd → u + β⁻ + $\overline{\nu}_e$
Cu → d + β⁺ + νe
Du → d + β⁺ + $\overline{\nu}_e$
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43May / June 2022 · Paper 13 · Q40Show mark scheme →
AA meson consists of three quarks.
BA proton is a baryon.
CA quark is a fundamental particle.
DThere are six flavours (types) of quark.
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44Feb / March 2022 · Paper 12 · Q40Show mark scheme →
Acharm and antiup
Bdown and antitop
Cstrange and antibottom
Dup and antistrange
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45Oct / Nov 2021 · Paper 11 · Q40Show mark scheme →
Au u u
Bu u d
Cu d d
Dd d d
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46Oct / Nov 2021 · Paper 12 · Q40Show mark scheme →
AAn antineutrino is a fundamental particle.
BAn electron is made up of a quark and an antiquark.
CA neutrino is a lepton.
DA neutron is composed of three quarks.
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47Oct / Nov 2021 · Paper 13 · Q40Show mark scheme →
AΣ– : dds
BΣ+ : uds
Cp : uud
Dn : udd
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48May / June 2021 · Paper 11 · Q40Show mark scheme →
Aelectron
Bhadron
Cneutron
Dproton
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49May / June 2021 · Paper 12 · Q40Show mark scheme →
AThe number of down quarks decreases by one.
BThe number of down quarks increases by one.
CThe number of down quarks stays the same.
DThe number of up quarks stays the same.
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50May / June 2021 · Paper 13 · Q40Show mark scheme →
Adown, down, up
Bdown, up, strange
Cup, strange, strange
Dup, up, strange
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51Feb / March 2021 · Paper 12 · Q40Show mark scheme →
A$^{1}_{1}\text{H}$
B$^{4}_{2}\text{He}$
C$^{7}_{3}\text{Li}$
D$^{9}_{4}\text{Be}$
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52Oct / Nov 2020 · Paper 11 · Q40Show mark scheme →
Au̅ d̅ d̅
Bu̅ u̅ d̅
Cu d d
Du u d
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53Oct / Nov 2020 · Paper 12 · Q40Show mark scheme →
Aelectron
Bneutrino
Cpositron
Dproton
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54Oct / Nov 2020 · Paper 13 · Q40Show mark scheme →
Aalpha-particle
Belectron
Cneutron
Dproton
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55May / June 2020 · Paper 11 · Q40Show mark scheme →
Addd
Budd
Cuud
Duuu
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56May / June 2020 · Paper 12 · Q40Show mark scheme →
Asss
Buss
Cuus
Duuu
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57May / June 2020 · Paper 13 · Q40Show mark scheme →
Addu → uud + β+ + ν
Bddu → uud + β+ + ν̄
Cuud → ddu + β+ + ν
Duud → ddu + β+ + ν̄
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58Feb / March 2020 · Paper 12 · Q40Show mark scheme →
Aneutron, hadron, u u d
Bneutron, lepton, u d d
Cproton, hadron, u u d
Dproton, lepton, u d d
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59Oct / Nov 2019 · Paper 11 · Q40Show mark scheme →
Ad d s
Bs d s
Cs u s
Du u s
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60Oct / Nov 2019 · Paper 12 · Q39Show mark scheme →
Aelectron
Bneutrino
Cneutron
Dpositron
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61Oct / Nov 2019 · Paper 12 · Q40Show mark scheme →
A+1 up quarks, 0 down quarks
B+1 up quarks, –1 down quarks
C–1 up quarks, +1 down quarks
D0 up quarks, +1 down quarks
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62Oct / Nov 2019 · Paper 13 · Q40Show mark scheme →
AElectrons and neutrinos are fundamental particles.
BElectrons and neutrinos are hadrons.
CProtons and neutrons are leptons.
DProtons and neutrons are quarks.
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63May / June 2019 · Paper 11 · Q40Show mark scheme →
Aup, down, down
Bup, strange, strange
Cup, up, down
Dup, up, up
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64May / June 2019 · Paper 12 · Q39Show mark scheme →
Adown → up + positron + electron neutrino
Bdown → up + positron + electron antineutrino
Cup → down + positron + electron neutrino
Dup → down + positron + electron antineutrino
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65May / June 2019 · Paper 12 · Q40Show mark scheme →
Aelectron | proton and neutron
Bneutron | proton and electron
Cproton and electron | neutron
Dproton and neutron | electron
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66May / June 2019 · Paper 13 · Q40Show mark scheme →
AA down quark changes to an up quark, and an electron and an electron antineutrino are emitted.
BA down quark changes to an up quark, and a positron and an electron neutrino are emitted.
CAn up quark changes to a down quark, and an electron and an electron antineutrino are emitted.
DAn up quark changes to a down quark, and a positron and an electron neutrino are emitted.
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67Oct / Nov 2018 · Paper 11 · Q40Show mark scheme →
Aup quarks 51, down quarks 60
Bup quarks 54, down quarks 57
Cup quarks 57, down quarks 54
Dup quarks 60, down quarks 51
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68Oct / Nov 2018 · Paper 12 · Q40Show mark scheme →
Aup
Bdown
Cstrange
Danti-strange
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69Oct / Nov 2018 · Paper 13 · Q40Show mark scheme →
AThe number of down quarks decreases by one.
BThe number of down quarks increases by one.
CThe number of down quarks stays the same.
DThe number of up quarks stays the same.
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70May / June 2018 · Paper 11 · Q38Show mark scheme →
Aproton
Bneutron
Celectron
Dquark
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71May / June 2018 · Paper 11 · Q39Show mark scheme →
A2
B3
C4
D5
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72May / June 2018 · Paper 12 · Q40Show mark scheme →
Ad → u + β⁻ + νe
Bd → u + β⁻ + $\bar{\nu}_e$
Cu → d + β⁺ + νe
Du → d + β⁺ + $\bar{\nu}_e$
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73May / June 2018 · Paper 13 · Q40Show mark scheme →
Aelectron, neutrino, positron
Belectron, neutrino, proton
Celectron, proton, neutron
Dneutrino, neutron, positron
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74Feb / March 2018 · Paper 12 · Q40Show mark scheme →
Aneutron: down, down, up; proton: down, up, up; type of force: strong interaction
Bneutron: down, down, up; proton: down, up, up; type of force: weak interaction
Cneutron: down, up, up; proton: down, down, up; type of force: strong interaction
Dneutron: down, up, up; proton: down, down, up; type of force: weak interaction
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75Oct / Nov 2017 · Paper 11 · Q40Show mark scheme →
A4 5
B5 4
C5 7
D7 5
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76Oct / Nov 2017 · Paper 12 · Q40Show mark scheme →
Au u u
Bu u d
Cu d d
Dd d d
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77Oct / Nov 2017 · Paper 13 · Q40Show mark scheme →
Au u u
Bu u d
Cu d d
Dd d d
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78May / June 2017 · Paper 11 · Q40Show mark scheme →
Aproton: up quark 1, down quark 1; neutron: up quark 2, down quark 2
Bproton: up quark 1, down quark 2; neutron: up quark 2, down quark 1
Cproton: up quark 2, down quark 1; neutron: up quark 1, down quark 2
Dproton: up quark 2, down quark 2; neutron: up quark 1, down quark 1
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79May / June 2017 · Paper 12 · Q40Show mark scheme →
Adown to up, antineutrino
Bdown to up, neutrino
Cup to down, antineutrino
Dup to down, neutrino
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80May / June 2017 · Paper 13 · Q40Show mark scheme →
Aelectron
Bhadron
Cneutron
Dproton
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81Feb / March 2017 · Paper 12 · Q40Show mark scheme →
Aantineutrino
Bdown quark
Cpositron
Dup quark
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82Oct / Nov 2016 · Paper 11 · Q38Show mark scheme →
Aa hadron
Ba particle consisting of two down quarks and one up quark
Ca positive fundamental particle
Da positive lepton
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83Oct / Nov 2016 · Paper 12 · Q40Show mark scheme →
Adiagram A
Bdiagram B
Cdiagram C
Ddiagram D
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84Oct / Nov 2016 · Paper 13 · Q38Show mark scheme →
Aa hadron
Ba particle consisting of two down quarks and one up quark
Ca positive fundamental particle
Da positive lepton
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85May / June 2016 · Paper 11 · Q38Show mark scheme →
AA down quark changes to an up quark and emits an electron and an electron antineutrino.
BA down quark changes to an up quark and emits a positron and an electron neutrino.
CAn up quark changes to a down quark and emits an electron and an electron antineutrino.
DAn up quark changes to a down quark and emits a positron and an electron neutrino.
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86May / June 2016 · Paper 12 · Q39Show mark scheme →
Aprotons hadrons, electrons leptons, neutrinos hadrons
Bprotons hadrons, electrons leptons, neutrinos leptons
Cprotons leptons, electrons hadrons, neutrinos hadrons
Dprotons leptons, electrons hadrons, neutrinos leptons
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87May / June 2016 · Paper 13 · Q40Show mark scheme →
Au: +2/3, d: −1/3, ū: +2/3, d̄: −1/3
Bu: −2/3, d: +1/3, ū: +2/3, d̄: −1/3
Cu: +2/3, d: −1/3, ū: −2/3, d̄: +1/3
Du: −2/3, d: +1/3, ū: −2/3, d̄: +1/3
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