Question
Fri June 08, 2012 By: Tabish

photon

Expert Reply
Fri June 08, 2012
The subatomic particle that carries the electromagnetic force and is the quantum of electromagnetic radiation. The photon has a rest mass of zero, but has measurable momentum, exhibits deflection by a gravitational field, and can exert a force. It has no electric charge, has an indefinitely long lifetime, and is its own antiparticle.
Ask the Expert