Lesson 8.4.2

8.4.2 Conservation laws and particle equations Quiz: Pearson Edexcel Physics, Unit 8

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 8.4.2, Conservation laws and particle equations: 20 multiple choice questions for the Pearson Edexcel Physics (9PH0), Unit 8: Nuclear and Particle Physics, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. Which quantity must always be conserved in particle interactions?

    • Quark flavour
    • Velocity
    • Kinetic energy
    • Baryon number

  2. What is the baryon number of an antiproton?

    • +2
    • +1
    • 0
    • -1

  3. What is the lepton number of an electron antineutrino?

    • 0
    • -1
    • +1
    • +2

  4. What is the total charge of a pion-plus and a neutrino?

    • -1 e
    • 0
    • +1 e
    • +2 e

  5. In the decay mu^- -> e^- + anti-nu_e + nu_mu, what is the total lepton number of the products?

    • +1
    • +2
    • -1
    • 0

  6. A neutron decays by n -> p + e^- + anti-nu_e. What is the total lepton number of the products?

    • -1
    • 0
    • +2
    • +1

  7. The reaction p + p -> p + n + pi^+ occurs. What is the total electric charge after the reaction?

    • 0
    • +3
    • +2
    • +1

  8. In the decay pi^- -> mu^- + X, which particle is X?

    • The antimuon neutrino
    • The electron antineutrino
    • A photon
    • The muon neutrino

  9. In the reaction e^- + p -> n + X, what is particle X?

    • The electron antineutrino
    • A positron
    • A photon
    • The electron neutrino

  10. A proton and a neutron collide, and the products are a proton and a particle X, with charge conserved. What is the charge of X?

    • +1
    • +2
    • Zero
    • -1

  11. A proton and a neutron are at rest, and a neutral particle X is produced with the other products. Which particle matches the requirement of zero charge?

    • A positive pion
    • A negative pion
    • A positron
    • A neutral pion

  12. Why can a neutron at rest not decay into a proton and negative pion?

    • Mass-energy conservation
    • Charge conservation
    • Baryon conservation
    • Lepton conservation

  13. Which equation is NOT consistent with conservation of electric charge?

    • n -> p + e^- + anti-nu_e
    • pi+ -> mu+ + nu_mu
    • pi+ -> mu- + nu_mu
    • pi^- -> mu^- + anti-nu_mu

  14. A mu-plus decays into an e-plus, an electron neutrino and an antimuon neutrino. What is the total lepton number of the products?

    • +1
    • -2
    • 0
    • -1

  15. In beta-plus decay, p -> n + e^+ + nu_e. What is the total lepton number of the products?

    • -1
    • +2
    • +1
    • 0

  16. In neutron beta-minus decay, which particle must accompany the electron to conserve lepton number?

    • The electron neutrino
    • The electron antineutrino
    • A positron
    • A photon

  17. Which particle equation is balanced for both charge and lepton number?

    • nu_mu + n -> p + mu^-
    • nu_mu + n -> p + mu^+
    • nu_mu + n -> n + mu^-
    • anti-nu_mu + n -> p + mu^-

  18. Which particle has baryon number -1 and electric charge -1?

    • The positron
    • The antiproton
    • The electron antineutrino
    • The antineutron

  19. Besides charge and baryon number, which property must be conserved in particle decay?

    • Parity
    • Spin direction
    • Lepton number
    • Strangeness

  20. Which particle equation is forbidden by conservation of lepton number?

    • pi+ -> e+ + nu_e
    • pi- -> e- + anti-nu_e
    • pi+ -> e+ + anti-nu_e
    • pi0 -> gamma + gamma

All Pearson Edexcel Physics quizzes