Particles and Radiation | AQA A-Level Physics (7408)
Particles and Radiation
- 314 questions
- 11 subtopics
- Paper 1, and available on Paper 3
- Paper 1 and Paper 3
Particles and radiation is examined on Papers 1 and 3.
It builds the atom from its constituents, introduces antimatter and the exchange particles that carry the four interactions, classifies hadrons and leptons, and closes on the photon and wave-particle duality.
Sample questions from Particles and Radiation
Answer each one closed book first, then open the answer.
-
Constituents of the atom
What is the relative mass of a proton?
Show the answer
1. -
Stable and unstable nuclei
Why do unstable nuclei undergo radioactive decay?
Show the answer
To become more stable by emitting radiation. -
Particles, antiparticles and photons
According to the photon model, how is electromagnetic radiation emitted and absorbed?
Show the answer
As discrete packets of energy called photons. -
Particle interactions
Which fundamental interaction is responsible for electron capture?
Show the answer
The weak interaction. -
Classification of particles
How does the baryon number of a meson compare with that of a baryon?
Show the answer
A meson has baryon number 0, whereas a baryon has baryon number +1 (or −1 for an antibaryon). -
Quarks and antiquarks
State the quark composition of a proton.
Show the answer
uud (two up quarks and one down quark) -
Applications of conservation laws
State the conservation law for baryon number in particle physics.
Show the answer
Baryon number is conserved in all particle interactions. -
The photoelectric effect
If photons of frequency below the threshold frequency are incident on a metal, why can electrons not accumulate energy from multiple photons to escape?
Show the answer
Each photon interacts with only a single electron, so an electron cannot accumulate energy from multiple photons; a single photon must provide all the energy needed to overcome the work function.
The 11 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Constituents of the atom | Protons, neutrons and electrons, nucleon and proton number, isotopes, and specific charge. | 35 |
| Stable and unstable nuclei | Alpha, beta-minus and beta-plus decay, and why the neutrino had to be proposed. | 25 |
| Particles, antiparticles and photons | Antiparticles, rest energy in MeV, the photon model, and annihilation and pair production. | 32 |
| Particle interactions | The four fundamental interactions and their exchange particles, and Feynman diagrams for beta decay and electron capture. | 32 |
| Classification of particles | Hadrons and leptons, baryons and mesons, and the baryon, lepton and strangeness numbers. | 48 |
| Quarks and antiquarks | The up, down and strange quarks and their properties, and the quark composition of baryons and mesons. | 39 |
| Applications of conservation laws | Checking charge, baryon number, lepton number and strangeness to decide whether an interaction can happen. | 20 |
| The photoelectric effect | Threshold frequency, the work function, the photoelectric equation and stopping potential. | 21 |
| Collisions of electrons with atoms | Excitation and ionisation, the electron volt, and how a fluorescent tube works. | 18 |
| Energy levels and photon emission | Discrete energy levels, emission and absorption line spectra, and the diffraction grating. | 27 |
| Wave-particle duality | The de Broglie wavelength, electron diffraction, and how scientific ideas are tested and accepted. | 17 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
-
Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
-
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
-
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
AQA A-Level Physics Active Recall Guide
Every topic, not just this one. 3,682 questions with their answers.