Quark fractional charges sum to integer hadron charges

Steps:

• Hadrons like baryons consist of three quarks.
• Quarks carry fractional charges: +2/3 e (up-type) or -1/3 e (down-type).
• Identical charge means all three have -1/3 e (e.g., down quarks in Δ⁻ baryon).
• Total charge = 3 × (-1/3 e) = -e, with magnitude e.

Why B is correct:

• Three quarks each with -1/3 e yield total charge -e, so the value is e (listed as +e).

Why the others are wrong:

• A. 0e: Three identical fractional charges cannot sum to zero.
• C. +2e: Requires +2/3 e per quark, not the -1/3 e case for e.
• D. +3e: Exceeds possible sum (maximum 3 × 2/3 e = +2e).

Final answer: B