Identify the smallest subatomic particle

The smallest subatomic particle is the quark. Quarks are fundamental particles that combine to form protons and neutrons, which are the building blocks of atomic nuclei. They come in six flavors: up, down, charm, strange, top, and bottom. Quarks are unique in that they carry fractional electric charges, unlike protons and electrons, which carry whole-number charges.

Quarks are not found freely in nature; they always combine with other quarks to form composite particles known as hadrons, such as protons and neutrons. The characteristics of quarks and their interactions are described by quantum chromodynamics (QCD), a fundamental theory in particle physics. While electrons are another type of subatomic particle, they are not smaller than quarks; in fact, quarks are considered to be point-like in nature, meaning they have no known substructure or size, making them the smallest constituents in the hierarchy of matter.