In particle physics, a proton is a type of baryon, which is a composite subatomic particle made up of three quarks held together by the strong force. Specifically, a proton is composed of two up quarks (u) and one down quark (d).
The properties of quarks contribute to the proton's overall characteristics:
- Up quarks have a charge of +2/3e (where e is the elementary charge).
- Down quarks have a charge of -1/3e.
Combining the charges of the up and down quarks in a proton:
- Two up quarks: [tex]\(2 \times \left(\frac{+2}{3}\right)e = \frac{+4}{3}e\)[/tex]
- One down quark: [tex]\(\frac{-1}{3}e\)[/tex]
Adding these charges together gives:
[tex]\[ \frac{+4}{3}e + \frac{-1}{3}e = \frac{+3}{3}e = +1e \][/tex]
Therefore, the overall charge of a proton is +1e, which is consistent with its known positive electric charge.
In summary, the quark composition of a proton is:
[tex]\[ \text{up (u)}, \text{up (u)}, \text{down (d)} \][/tex]
So the correct answer is:
[tex]\[ \boxed{\text{u, u, d}} \][/tex]
