In what ways do photons resemble and differ from other particles. What are some of their properties?
Photons like all other particles display a wave-particle duality. This can be seen easily. The passage of light through a lens displays their behavior as a wave and their particle nature can be seen by their interaction with a photo voltaic cell. Only photons with sufficient energy result in electrons being emitted.
Unlike particles like electrons, photons do not have a rest mass. They also do not have any charge. All photons travel at a constant speed which depends only on the material through which they are travelling. The difference in energy that photons display is due to a difference in their frequency. As the frequency of a photon increases, so does its energy.