AS Level Physics chapter 11: Particle physics MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

53 exam-style questions on Particle physics, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

53 questions · 2 topics · 10 per test

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What chapter 11 covers

Ten Particle physics questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. What is the charge of an antiproton?

  1. A
    +1
  2. B
    0
  3. C
    −1
  4. D
    +2
Show answer

Answer: C. Antiparticles have the same mass and opposite charge: the antiproton (anti-up, anti-up, anti-down) has charge −1.

2. Which statement about hadrons is correct?

  1. A
    baryons and mesons are both hadrons
  2. B
    all hadrons are made of three quarks
  3. C
    electrons are hadrons
  4. D
    mesons are made of three antiquarks
Show answer

Answer: A. Hadrons are particles made of quarks: baryons (three quarks) and mesons (a quark and an antiquark). Electrons are leptons.

3. α-particles from one nuclide have discrete energies, but β-particles from one nuclide have a continuous range of energies. Why?

  1. A
    β-particles are slowed by collisions inside the nucleus
  2. B
    β-particles have a smaller charge than α-particles
  3. C
    β-particles are much lighter than α-particles
  4. D
    in β-decay the energy released is shared between the β-particle and an (anti)neutrino
Show answer

Answer: D. The decay energy is fixed, but in β-decay it is split in varying proportions between the β-particle and the (anti)neutrino, so the β-particle can have any energy up to a maximum.

4. Which list contains only fundamental particles?

  1. A
    proton, neutron, electron
  2. B
    pion, electron, neutrino
  3. C
    electron, electron neutrino, charm quark
  4. D
    neutron, up quark, positron
Show answer

Answer: C. Leptons (electron, neutrino) and quarks are fundamental. Protons, neutrons and pions are hadrons made of quarks.

5. A nitrogen nucleus absorbs an α-particle: 147N + 42He → 178O + X. What is particle X?

  1. A
    a neutron
  2. B
    a proton
  3. C
    an electron
  4. D
    an α-particle
Show answer

Answer: B. Nucleon number: 14 + 4 = 17 + A, so A = 1. Charge: 7 + 2 = 8 + Z, so Z = 1. A particle with A = 1 and Z = 1 is a proton.

6. A proton is made of which quarks?

  1. A
    uud
  2. B
    udd
  3. C
    uds
  4. D
    uuu
Show answer

Answer: A. Proton = up, up, down: charge (+2/3) + (+2/3) + (−1/3) = +1. A neutron is udd.

7. An ion of aluminium, 2713Al, has a charge of +3e. How many orbital electrons does it have?

  1. A
    10
  2. B
    13
  3. C
    14
  4. D
    16
Show answer

Answer: A. A neutral atom has 13 electrons (equal to the proton number). A charge of +3e means 3 electrons have been lost, leaving 10. 14 is the number of neutrons.

8. In the simple nuclear model of the atom, which particles are found in the nucleus?

  1. A
    protons and electrons
  2. B
    protons only
  3. C
    protons and neutrons
  4. D
    neutrons and electrons
Show answer

Answer: C. The nucleus contains protons and neutrons (nucleons). The electrons are outside the nucleus, orbiting it.

9. A meson consists of

  1. A
    three quarks
  2. B
    a quark and an antiquark
  3. C
    two quarks
  4. D
    a lepton and a quark
Show answer

Answer: B. Baryons (proton, neutron) are three quarks; mesons are quark–antiquark pairs. Both are hadrons.

10. How many up quarks and how many down quarks are there in a nucleus of 73Li?

  1. A
    6 up and 8 down
  2. B
    9 up and 12 down
  3. C
    10 up and 11 down
  4. D
    11 up and 10 down
Show answer

Answer: C. 3 protons (up, up, down) give 6 up and 3 down; 4 neutrons (up, down, down) give 4 up and 8 down. Total: 10 up and 11 down.

Start the chapter testAbout the AS Level Physics test

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Ways to practise this chapter

Particle physics: questions students ask

How many Particle physics MCQs are there?

53, each with the answer and a short explanation, across 2 topics: Atoms, nuclei and radiation, Fundamental particles. Every chapter test draws ten of them, so you can take it many times.

Is the AS Level Physics chapter 11 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

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