Planck's constant (redirected from Planck constant)

Planck's constant (plängks)

n.

Symbol h The constant of proportionality relating the energy of a photon to the frequency of that photon. Its value is approximately 6.626 × 10^-34 joule-second.

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Planck's constant (h)

[plangks]

Etymology: Max Planck, German physicist, 1858-1947

a fundamental physical constant that relates the energy of radiation to its frequency. It is expressed as 6.63 × 10^-27 erg-seconds or 6.63 × 10^-34 joule-seconds. See also photon.

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photon 

The basic unit of radiant energy defined by the equation

E = hν

where h is Planck's constant (6.62 ✕ 10⁻³⁴ joule ✕ second), ν the frequency of the light and E the energy difference carried away by the emission of a single photon of light. The term photon usually refers to visible light whereas the term quantum refers to other electromagnetic radiations. See quantum theory; wave theory; troland.