Quarks combine to form composite particles called hadrons. The most stable of which are protons and neutrons, the components of atomic nuclei.
There are six types, known as flavors, of quarks: up, down, charm, strange, top, and bottom. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, besides fundamental forces (electromagnetism, gravitation, strong interaction and weak interaction).
The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. There was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968.
Source:
[1] Wikipedia Contributors. “Quark.” Wikipedia, Wikimedia Foundation, 2 Jan. 2021, en.wikipedia.org/wiki/Quark. Accessed 5 Jan. 2021.
[2] GDJ. “Mandala Decorative Ornamental – Free Vector Graphic on Pixabay.” Pixabay.com, 21 Sept. 2017, pixabay.com/vectors/mandala-decorative-ornamental-2773487/. Accessed 6 Jan. 2021.