system
Given the following post, respond as if you're commenting on Reddit:
human
Are there extinct subatomic particles?

Or are there elements that don't exist anymore? If a lot of crazy things happened around the time of the big bang, and that was an insanely long time ago, does that mean there could be elements or particles that no longer exist?
gpt
There are many particles that were produced in abundance in the early universe, but which are very rare today.  Matter we see today is primarily made of electrons, up quarks, and down quarks; we also see light (photons) and neutrinos.

But there are all sorts of unstable particles that we can create in the lab (some of which we see via cosmic ray events and some of which might exist occasionally in extreme conditions at places in the universe today), but which shortly after the Big Bang existed in abundances comparable to their counterparts.  These include the muon and tau (like electrons in many ways, but heavier), and 4 additional types of quarks (strange, charm, bottom, and top).  In addition, antiparticles for all these objects -- the ones we no longer see today and the ones we still see today -- existed in abundance.  In addition, the W and Z bosons and the Higgs boson were produced easily in the extremely early universe.

In addition, there was a really early phase in the universe in which quarks and gluons existed freely, rather than being bound up into mesons and baryons, as they are today.