mole

Post date: Oct 16, 2015 11:47:38 PM

The mole is a unit of measurement for amount of substance. It is defined as the amount of any chemical substance that contains as many elementary entities, e.g.,atoms, molecules, ions, or electrons, as there are atoms in 12 grams of pure carbon-12 (12C), the isotope of carbon with relative atomic mass 12 by definition. This number is expressed by the Avogadro constant, which has a value of 6.022×1023