4.5.121 - Standard quark-lepton model

Know that in the standard quark-lepton model particles can be classified as: baryons (e.g. neutrons and protons), which are made from three quarks mesons (e.g. pions), which are made from a quark and an antiquark leptons (e.g. electrons and neutrinos), which are fundamental particles photons and that the symmetry of the model predicted the top quark.

Use - standard quark-lepton model to connect the rule to the data and decision in the question.

This matters because - standard quark-lepton model determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - standard quark-lepton model to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Standard quark-lepton model is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.