Everything in universe is composed of atoms, and each item has a likewise constant composition. This includes three major subatomic particles, the proton, the neutron, and the electron. Within the center of the atom are the protons and neutrons. The electrons surround them in arcs. Protons have the largest masses of these particles and also are the only one to have a positive electric charge, which is the antithesis to the electron's negative charge.
Eugene Goldstein first theorized the existence of the proton not long after discovery of the electron by J.J. Thomson. Electrons where observed to have a negative charge, but the atoms they were part of had a neutral charge. That meant that there would have to be a positively charged ion to counteract the electron. Goldstein went looking for the proton, but failed. Ernest Rutherford, in 1918, is credited with actually discovering the particle when he shot alpha particles into nitrogen and found the positively charged hydrogen nuclei, which was composed of a proton.
Protons are particles that are held together with neutrons by nuclear forces in order to create an atomic nucleus. All atomic particles have a particular spin that affects their movement, among other things, and for protons this spin is -1/2. Protons themselves are made up even smaller particles called quarks. There are up and down quarks and the proton is composed of two ups and one down. They are held to each other by tiny subatomic particles called gluons.
The number of protons in an atom affects the chemical makeup of the atom they are a part of. An atom can have any number of electron or neutrons and their chemical properties will not be affected. Because this effect, the number of protons in an atom is directly proportional to its place on the periodic table of elements. For example, Hydrogen, which has one proton, takes up space number 1 on the table, and so on.
Protons are a significant ion not only because of the way they affect an atom's chemical makeup but also for the role they play in the study of high energy and theoretical physics. Today, some of the most amazing discoveries in particle physics are being made by energizing atom smashers, such as the one built by CERN. Since protons have a large mass compared to electrons and are generally stable, they are perfect for use in these tests. Therefore, they make studying effects of particle collisions and thus smaller particles in general easier for scientists.
Compared to the other ions and particles in an atom, the proton has the largest mass. In relation to the electron, which is the polar opposite of the proton, it has a mass 1,836 times the negatively charged ion. While their size is larger than both the electron and the neutron, they do not take up as much space in an atom because there will always be more electrons and neutrons than protons present.