This could be a very long answer! In essence, some particle physics is introduced even in the IGCSE exam (14-16 yo) but the discussion of the fundamental concepts is left out!

The first introduction concerns an explanation of beta decay in terms of a neutron miraculously changing into a proton, electron and anti-neutrino. The syllabus goes as deep as the down quark changing to an up quark. The why of it all is left for the future.

Indeed, the bizarre introduction of the anti-neutrino is left unexplained, even though the concept of spin is later crucial when learning how an MRI machine works - but even then, particle spin is not officially in the syllabus.

I will very soon write on a recent experience at A level (16-18 yo) physics, teaching the production of X-rays by electron transitions. I do not expect a university level explanation as students lack the mathematical tools, but, again, the fundamental ideas are missing. Students need to express complex ideas parrot-fashion without much understanding.

I wish schools would teach engineering and thereby clean up the physics syllabus, and bring mathematics back into it.