Quark composition of tritium nucleus

Steps:

• Hydrogen-3 (tritium) nucleus has 1 proton and 2 neutrons.
• Proton consists of 2 up quarks and 1 down quark (uud).
• Each neutron consists of 1 up quark and 2 down quarks (udd).
• Total: 2 up + 2(1 up) = 4 up quarks; 1 down + 2(2 down) = 5 down quarks.

Why A is correct:

• Matches the exact quark count from 1 proton (uud) and 2 neutrons (2×udd), totaling 4 up and 5 down.

Why the others are wrong:

• B: Swaps up/down counts, ignoring neutron's extra down quarks.
• C: Overcounts down quarks, possibly confusing with electron or other particles.
• D: Overcounts up quarks, mistaking for more protons.

Final answer: A