Amount of substance mole

Amount of substance mole mol Amount of substance which contains as many specified entities as there are atoms of car-bon-12 in exactly 0.012 kg of that nuclide. The elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. 

Amount of substance mole mol The mole is the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012kg of Carbon 12. 

Amount of substance Mole mole 1 Mole mole... 

The most important modem system of units is the SI system, which is based around seven primary units time (second, abbreviated s), length (meter, m), temperature (Kelvin, K), mass (kilogram, kg), amount of substance (mole, mol), current (Amperes, A) and luminous intensity (candela, cd). The candela is mainly important for characterizing radiation sources such as light bulbs. Physical artifacts such as the platinum-iridium bar mentioned above no longer define most of the primary units. Instead, most of the definitions rely on fundamental physical properties, which are more readily reproduced. For example, the second is defined in terms of the frequency of microwave radiation that causes atoms of the isotope cesium-133 to absorb energy. This frequency is defined to be 9,192,631,770 cycles per second (Hertz) —in other words, an instrument which counts 9,192,631,770 cycles of this wave will have measured exactly one second. Commercially available cesium clocks use this principle, and are accurate to a few parts in 1014. 

Concentration (of amount of substance) mole per cubic meter mol/m2... 

The raison d etre of reference materials is to provide traceability. Ultimately and ideally all chemical analyses will be traceable to an SI unit, the amount of substance (mole) or mass (kg). In this way, agreement between different analysts, laboratories, and countries is enhanced. 

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