Which statements are true? Select those that apply.
a) A photon has spin angular momentum
b) Radio waves, such as those that carry FM music or television, are actually quanta or packets of energy, just like visible light
c) The photon has energy proportional to its frequency
d) Gamma "rays" or gamma particles, emitted by radioactive atoms, have mass
e) All photons travel with the speed "c" or 3x108 m/s in a vacuum regardless of their energy