Particles and Radiation

Particle physics explores the fundamental building blocks of matter and the forces that govern their interactions. At A-Level, this topic introduces the Standard Model, the classification of particles, radioactive decay processes, the photoelectric effect, and wave-particle duality. This is one of the most conceptually rich areas of A-Level Physics.

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The Standard Model

The Standard Model is the most successful theory describing the fundamental particles and three of the four fundamental forces (electromagnetic, weak nuclear, and strong nuclear). Gravity is not yet incorporated into the Standard Model.

Key Definition: The Standard Model is a theoretical framework that classifies all known fundamental particles and describes the electromagnetic, weak nuclear, and strong nuclear interactions between them.

Fundamental Particles

All known matter is composed of two families of particles:

• Quarks — which experience the strong nuclear force
• Leptons — which do not experience the strong nuclear force

Quarks

There are six flavours of quark, arranged in three generations: