pho·ton
 
 /ˈfoʊ
tɒn/
Show Spelled[foh-ton]
–noun a quantum of electromagnetic radiation, usually considered as an elementary particle that is its own antiparticle and that has zero rest
mass and charge and a spin of one. Symbol: γ
Also called
light quantum.
Origin:
1900–05;
phot- +
-on1
Cultural Dictionary
photon [( foh -ton)]
The
quantum, or bundle of
energy, in which
light and other forms of
electromagnetic radiation are emitted. (
See atom.)
Science Dictionary
photon (fō'tŏn')
Pronunciation Key
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. See Note at
electromagnetic radiation. See Table at
subatomic particle.