Answer:
Quarks
Explanation:
Quarks are the smallest constituents of protons and neutrons. In particular, the proton and the neutron are a combination of two types of quarks:
- Quark up: it has a charge of [tex]+\frac{2}{3}e[/tex]
- Quark down: it has a charge of [tex]-\frac{1}{3}e[/tex]
Both the proton and the neutron consists of 3 quarks:
- The proton consists of 2 quarks up and 1 quark down, so that its charge is
[tex]q_p = +\frac{2}{3}e+\frac{2}{3}e-\frac{1}{3}e = +e[/tex]
- The neutron consists of 1 quark up and 2 quarks down, so that its charge is
[tex]q_n = +\frac{2}{3}e-\frac{1}{3}e-\frac{1}{3}e = 0[/tex]
