The energy of one of these is equal to Planck's constant times its frequency.
The ratio of the rate of emission of these particles to Auger ionization is proportional to the third power of atomic number. Dust particles lose momentum after interaction with these particles in Poynting-Robertson drag. Pair production generates an electron and positron from one of these particles. One cross-section for scattering of these particles by charges is given by eight pi over three times the square of the classical particle radius, that being the Thompson cross-section; another such cross-section is the Klein-Nishina formula. The energy of one of these is equal to Planck's constant times its frequency. For 10 points, name these particles that carry the electromagnetic force and travel at the speed of light because they are the quanta of light.
The ratio of the rate of emission of these particles to Auger ionization is proportional to the third power of atomic number.
{photons}