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Mach number

(Encyclopedia)Mach number mäk [key] [for E. Mach], ratio between the speed of an object and the speed of sound in the medium in which the object is traveling. An airplane that has the velocity of Mach 3.0 is trave...

mass number

(Encyclopedia)mass number, often represented by the symbol A, the total number of nucleons (neutrons and protons) in the nucleus of an atom. All atoms of a chemical element have the same atomic number (number of pr...

rational number

(Encyclopedia)rational number: see number.

real number

(Encyclopedia)real number: see number.

transcendental number

(Encyclopedia)transcendental number: see number. ...

transfinite number

(Encyclopedia)transfinite number, cardinal or ordinal number designating the magnitude (power) or order of an infinite set; the theory of transfinite numbers was introduced by Georg Cantor in 1874. The cardinal num...

prime number

(Encyclopedia)prime number: see number theory. ...

Reynolds number

(Encyclopedia)Reynolds number [for Osborne Reynolds], dimensionless quantity associated with the smoothness of flow of a fluid. It is an important quantity used in aerodynamics and hydraulics. At low velocities flu...

oxidation number

(Encyclopedia)oxidation number or oxidation state: see valence. ...

mole, in chemistry

(Encyclopedia)mole, in chemistry, a quantity of particles of any type equal to Avogadro's number, or 6.02×1023 particles. One gram-molecular weight of any molecular substance contains exactly one mole of molecules...