How are quarks characterized in terms of charge?

Quarks are fundamental particles that serve as the building blocks of hadrons, such as protons and neutrons. They are characterized by having fractional electric charges, which distinguishes them from other particles, such as electrons or protons, that possess whole number charges.

The charges of quarks are quantified as either +2/3 or -1/3 of the elementary charge, which is the charge of a proton or the negative charge of an electron. This fractional charge characteristic is unique to quarks and is a key aspect of the theory of quantum chromodynamics, which describes the strong interactions between quarks and gluons.

In contrast, whole number charges are found in particles like protons, which have a charge of +1, or electrons, which have a charge of -1. Particles that carry no charge, such as neutrinos, completely lack electric charge, while opting for negative charges exclusively would overlook the positive charges associated with certain types of quarks. Therefore, understanding that quarks possess fractional charges is essential in the study of particle physics and contributes to our understanding of the interactions governing matter in the universe.