Question

It is now believed that protons and neutrons (which constitute nuclei of ordinary matter) are themselves built out of more elementary units called quarks. A proton and a neutron consist of three quarks each. Two types of quarks, the so-called 'up' quark (denoted by u) of charge + (2/3) e, and the 'down' quark (denoted by d) of charge (-1/3) e, together with electrons build up ordinary matter. (Quarks of other types have also been found which give rise to different unusual varieties of matter.) Suggest a possible quark composition of a proton and neutron

Answer 1

A proton is composed of two up quarks and one down quark (uud), giving it a charge of +1e. A neutron consists of one up quark and two down quarks (udd), resulting in a neutral charge. These compositions explain the electrical properties of these nucleons which constitute ordinary matter.

Step-by-step explanation:

Ordinary matter is composed primarily of the protons and neutrons, which are in turn made up of quarks. By examining the charge of the quarks, we can deduce the composition of these nucleons. A proton has a quark composition of two up quarks and one down quark (uud), giving it a total charge of +1 elementary charge (e). This is because each up quark has a charge of +2/3 e and the down quark has a charge of -1/3 e. When you add them up (+(2/3) e + (2/3) e - (1/3) e), you get +1 e, which is the charge of the proton.

In contrast, a neutron is composed of one up quark and two down quarks (udd). The charges of these quarks add up to zero ((+2/3) e - (1/3) e - (1/3) e = 0), which is why the neutron is electrically neutral. Both the proton and neutron are examples of baryons, which are particles made up of three quarks. The quarks within nucleons are held together by the strong force, one of the four fundamental forces in nature, which also includes the weak, electromagnetic, and gravitational forces.