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Avogadro's number

(Encyclopedia)Avogadro's number ävōgäˈdrō [key] [for Amedeo Avogadro], number of particles contained in one mole of any substance; it is equal to 602,252,000,000,000,000,000,000, or in scientific notation, 6.0...

Avogadro, Amedeo, conte di Quaregna

(Encyclopedia)Avogadro, Amedeo, conte di Quaregna ämādāˈō kônˈtā dē kwärāˈnyä ävōgäˈdrō [key], 1776–1856, Italian physicist, b. Turin. He became professor of physics at the Univ. of Turin in 182...

number

(Encyclopedia)number, entity describing the magnitude or position of a mathematical object or extensions of these concepts. A real or complex number z is called algebraic if it is the root of a polynomial equati...

algebraic number

(Encyclopedia)algebraic number: see number.

complex number

(Encyclopedia)complex number: see number.

imaginary number

(Encyclopedia)imaginary number: see number.

index number

(Encyclopedia)index number, in econometrics, a figure reflecting a change in value or quantity as compared with a standard or base. The base usually equals 100 and the index number is usually expressed as a percent...

atomic number

(Encyclopedia)atomic number, often represented by the symbol Z, the number of protons in the nucleus of an atom, as well as the number of electrons in the neutral atom. Atoms with the same atomic number make up a c...

number theory

(Encyclopedia)number theory, branch of mathematics concerned with the properties of the integers (the numbers 0, 1, −1, 2, −2, 3, −3, …). An important area in number theory is the analysis of prime number...

octane number

(Encyclopedia)octane number, figure of merit representing the resistance of gasoline to premature detonation when exposed to heat and pressure in the combustion chamber of an internal-combustion engine. Such detona...