Ordinary matter is made up of protons, neutrons and electrons. At the time they were
discovered, these particles were not thought to be made up of any other particles.
Explain how the proton, neutron and electron are described in the current standard
model of matter
Correct, uncontradicted reference to fundamental particles:
E.g., Electron is not made of any other particles
Or the electron is fundamental
Or the electron has no internal structure
Or Protons/neutrons are not fundamental
Protons/neutrons are baryons
Or electrons are leptons
Proton/neutron/baryon made of 3 quarks (accept the individual quark combinations
of proton and neutron)