Scientists Say: Photon
This particle represents a little packet of light
Lasers, like the one this researcher is using, create a beam of photons. The photons in a laser all have the same energy. Lasers can be used for all sorts of things, from studying chemical reactions as they happen to reading the information on a DVD to play a movie.
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Photon (noun, “FOH-TAHN”)
This word describes a particle of light. A photon is a unit of light that cannot be broken into smaller pieces. This particle is the tiniest possible packet of electromagnetic radiation.
Light’s motion is often described as a wave. But light also has some properties of a particle. One of those properties is that photons can be counted, like beads on a string.
Photons can have different energies. A photon of visible light, such as light that’s the color blue, has a lower energy than an X-ray photon. Scientists can use beams of high-energy X-ray photons to study the properties of matter and molecules.
In a sentence
Human eyes are sensitive enough to see a single photon.
