Of the following three categories of particles, the only group that contains particles with zero mass is the
A) baryons.
B) mesons.
C) leptons.
D) More than one of the previous responses are valid.

Question

Quizplus · Accepted Answer

Leptons include particles like neutrinos, which have an extremely small, but nonzero mass, and the electron, which also has mass. However, the photon, which is considered a gauge boson (not a lepton), actually has zero mass and is responsible for electromagnetic force. The confusion might stem from the fact that none of the given options perfectly fits the description of containing particles with zero mass, as leptons themselves do not include particles with zero mass. The correct category for particles with zero mass would be gauge bosons, not listed among the options. Given the options, none directly fit the criteria for containing particles with zero mass, suggesting a misunderstanding in the question's framing.

Of the Following Three Categories of Particles, the Only Group