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constant US English

Occurring continuously over a period of time

constant US Thesaurus

the constant background noise

gas constant US English

The constant of proportionality in the gas equation. It is equal to 8.314 joule kelvin1 mole1

rate constant US English

A coefficient of proportionality relating the rate of a chemical reaction at a given temperature to the concentration of reactant (in a unimolecular reaction) or to the product of the concentrations of reactants

time constant US English

A time that represents the speed with which a particular system can respond to change, typically equal to the time taken for a specified parameter to vary by a factor of 11e (approximately 0.6321)

Euler's constant US English

A constant used in numerical analysis, approximately equal to 0.577216. It represents the limit of the series 1 + 12 + 13 + 14 + ...1n − (natural logarithm of n), as n tends to infinity. It is not known whether this is a rational number or not

solar constant US English

The rate at which energy reaches the earth’s surface from the sun, usually taken to be 1,388 watts per square meter

coupling constant US English

A measure of the strength of interaction between two particles, or between a particle and a field

Faraday's constant US English

The quantity of electric charge carried by one mole of electrons (equal to 96.49 coulombs)

Hubble's constant US English

The ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer. The reciprocal of the constant is called Hubble time and represents the length of time for which the universe has been expanding, and hence the age of the universe

Lambert, Constant US English

(1905–51), English composer, conductor, and critic; full name Leonard Constant Lambert. He wrote the music for the ballet Romeo and Juliet (1926) and the jazz work The Rio Grande (1929), later becoming musical director of Sadler’s Wells (1930–47)

Michaelis constant US English

The concentration of a given enzyme that catalyzes the associated reaction at half the maximum rate

Planck's constant US English

A fundamental constant, equal to the energy of a quantum of electromagnetic radiation divided by its frequency, with a value of 6.626 × 1034 joule-seconds

Rydberg constant US English

A constant, 1.097 x 107 m−1, that appears in the formulae for the wave numbers of lines in atomic spectra and is a function of the rest mass and charge of the electron, the speed of light, and Planck’s constant

Boltzmann's constant US English

The ratio of the gas constant to Avogadro’s number, equal to 1.381 × 10-23 joules per kelvin in the case where the number of molecules is equal to Avogadro’s number

cosmological constant US English

An arbitrary constant in the field equations of general relativity

dielectric constant US English

A quantity measuring the ability of a substance to store electrical energy in an electric field

dissociation constant US English

A quantity expressing the extent to which a particular substance in solution is dissociated into ions, equal to the product of the concentrations of the respective ions divided by the concentration of the undissociated molecule

fine-structure constant US English

A fundamental and dimensionless physical constant, equal to approximately 1137, that occurs in expressions describing the fine structure of atomic spectra

gravitational constant US English

The constant in Newton’s law of gravitation relating gravity to the masses and separation of particles, equal to 6.67 × 1011N m2 kg2

Planck constant in Planck's constant US English

A fundamental constant, equal to the energy of a quantum of electromagnetic radiation divided by its frequency, with a value of 6.626 × 1034 joule-seconds

Avogadro's number US English

The number of atoms or molecules in one mole of a substance, equal to 6.023 × 1023

Avogadro's constant in Avogadro's number US English

The number of atoms or molecules in one mole of a substance, equal to 6.023 × 1023

k in Boltzmann's constant US English

The ratio of the gas constant to Avogadro’s number, equal to 1.381 × 10-23 joules per kelvin in the case where the number of molecules is equal to Avogadro’s number

sedimentation coefficient US English

A quantity related to the size of a microscopic particle, equal to the terminal outward velocity of the particle when centrifuged in a fluid medium divided by the centrifugal force acting on it, expressed in units of time

sedimentation constant in sedimentation coefficient US English

A quantity related to the size of a microscopic particle, equal to the terminal outward velocity of the particle when centrifuged in a fluid medium divided by the centrifugal force acting on it, expressed in units of time

Hubble's constant in Hubble New Oxford Dictionary for Writers & Editors

, Edwin Powell (1889–1953), American astronomer, who proposed Hubble's law and Hubble's constant

Leonard Constant Lambert in Lambert, Constant US English

(1905–51), English composer, conductor, and critic; full name Leonard Constant Lambert. He wrote the music for the ballet Romeo and Juliet (1926) and the jazz work The Rio Grande (1929), later becoming musical director of Sadler’s Wells (1930–47)