Q223 · Practice questionComplex familiar1 mark
QUESTION 223
Consider . Which listed particle can be X while conserving electric charge, total lepton number and baryon number?
(A)
A proton
(B)
A photon
(C)
(D)
WORKED SOLUTION
1 markAnswer C
ANSWER
C.
Worked solution
Initially , , . The electron and electron antineutrino already give , , , so X must be neutral, have and . Of these candidates, only satisfies all three. No extra family-number rule is needed to distinguish these options.
Equivalent physically justified methods and consistent equivalent units accepted.
Displayed decimals are model answers; accept appropriate significant figures and consistent rounding from stated constants.
Select C.
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