Planck's constant is a fundamental parameter in quantum mechanics. It determines the size of the discrete units or energy, mass, spin, etc. into which the microscopic world is partitioned. Its value is 1.05 x 10-27 grams-cm/sec.

universal constant that connects the energy of the photon (E) to its frequency (f) through the equation E=hf.

This is the lower limit to which energy and position can be measured simutaneously.

6.626× 10−34J s; a number used to calculate the radiant energy absorbed or emitted by a body from the frequency of the radiation; E = hν.

A fundamental physical constant, the elementary quantum of action, It is the ratio of the energy of a photon to its frequency and is equal to 6.62620 x 10-34 joule-second. Symbolized by .

proportionality constant, h, in the equation relating photon energy and frequency, nu. Energy=h x frequency. h=6.63E-34 Jás.

a universal constant that has a value of 6.63 x 10-34 J.

The ratio of the energy of a photon to its frequency; it is equal to 6.62620±0.00005 × 10-34 Joules-seconds.

The constant of proportionality relating the energy of a photon to its frequency.

Constant determining the relation between the energy E of a photon and its wavelength f. E=hf

The number that relates the energy and frequency of light; it has a value of 6.63 x 10-34 joule seconds.

Constant used to relate the frequency (n) or wavelength (l) of electromagnetic radiation to energy. (h = 6.62 x 10-^34 J sec.)

A universal constant, denoted by , with the value 6.626075 x 10−34 J s, in the quantum theory of matter and radiation. Planck's constant is the bridge between the wave and particle descriptions of light, an electromagnetic wave of frequency ν alternatively described as a stream of photons each with energy ν. According to the quantum theory, when the energy of an atom, molecule, or nucleus changes from one discrete energy level 1 to another conservation of energy requires the emission (creation) or absorption (annihilation) of a photon with energy given by the Einstein frequency condition Planck's constant is a fundamental scaling parameter of the universe, determining, among other things, the sizes of atoms and molecules.

Planck's constant (denoted h) is a physical constant that is used to describe the sizes of quanta. It plays a central role in the theory of quantum mechanics, and is named after Max Planck, one of the founders of quantum theory. A closely-related quantity is the reduced Planck constant (also known as Dirac's constant and denoted \hbar, pronounced "h-bar").