The Particles Hidden Inside Matter

Quarks are fundamental particles that form some of the basic building blocks of matter.

They combine to create particles called hadrons, including the protons and neutrons found inside atomic nuclei. As far as we currently know, quarks themselves are not made of anything smaller.

There are six types, or flavors, of quarks: up, down, charm, strange, top, and bottom.

Protons contain two up quarks and one down quark, while neutrons contain two down quarks and one up quark. Quarks are bound together by the strong nuclear force, one of the four fundamental forces of nature.

Nearly all ordinary matter around you is built from atoms whose nuclei contain protons and neutrons—and therefore quarks.

Understanding quarks helps us understand matter at one of its deepest known levels and reveals that even protons and neutrons are not truly indivisible.

You discovered that deep inside ordinary matter lies another layer of nature: quarks, some of the most fundamental particles we know.