What is a proton? Definition:

On proton (ancient Greek proto = first) is an electrically positively charged particle. The name goes back to the physicist Ernest Rutherford, who was the first experimental evidence of the existence of protons. Like neutrons, protons are in the nucleus. Thus, protons are among the nucleons (lat. nucleus = nucleus).
Protons (symbol: p+) consist of one down and two up quarks. The mass of a proton at 1.007 u is approximately that of a neutron. Compared to the electron, a proton is 2000 times larger. The corresponding antiparticle to the proton represents the antiproton.
The number of protons in the atomic nucleus determines the chemical element and this can be easily read in the periodic table by the atomic number. The atomic number, also called atomic number, namely corresponds to the number of protons in the atomic nucleus of the respective element. Thus, carbon has a total of six protons, because in the periodic table, it is listed under the atomic number 6. The arrangement in the periodic table is therefore not arbitrary, but depends on the physical properties of the elements.