Photon A "particle" of electromagnetic radiation

As we learned in the last section, an atom with excess energy is said to be in an excited state. An excited atom can release some or all of its excess energy by emitting a photon (a "particle" of electromagnetic radiation) and thus move to a lower energy state. The lowest possible energy state of an atom is called its ground state. 

Gamma photon a particle of electromagnetic radiation of short wavelength (about 1 pm, or 10 m) and high energy. (21.1) Gangue the worthless portion of an ore. (13.2)... 

Quantum (Section 13.4) The discrete amount of energy associated with a particle of electromagnetic radiation (i.e., a photon). 

In explaining the photoelectric effect, Albert Einstein proposed in 1905 that electromagnetic radiation has both wavelike and particlelike natures. That is, while a beam of light has many wavelike characteristics, it also can be thought of as a stream of tiny particles, or bundles of energy, called photons. Thus, a photon is a particle of electromagnetic radiation with no mass that carries a quantum of energy. 

A photon is a particle of electromagnetic radiation having zero mass and energy of hv. 

Photon A particle with energy but no at-rest mass. It represents a quantum of electromagnetic radiation. 

Light is a form of electromagnetic radiation and possesses characteristics of both waves and particles (photons). The energy of a photon is usually measured by the frequency (or by the wavelength in a... 

The particles of electromagnetic radiation are called photons, each having a discrete amount of energy called a quantum. Because electromagnetic radiation also has wave properties, it can be characterized by its wavelength and frequency. 

Colorimetry, in which a sample absorbs visible light, is one example of a spectroscopic method of analysis. At the end of the nineteenth century, spectroscopy was limited to the absorption, emission, and scattering of visible, ultraviolet, and infrared electromagnetic radiation. During the twentieth century, spectroscopy has been extended to include other forms of electromagnetic radiation (photon spectroscopy), such as X-rays, microwaves, and radio waves, as well as energetic particles (particle spectroscopy), such as electrons and ions. ... 

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