1 what is mole 2 define avogadro number

The mole, abbreviated mol, is an SI unit which measures the number of particles in a specific substance. One mole is equal to 6.02214179 × 1023 atoms, or other elementary units such as molecules One mole of oxygen atoms contains 6.02214179×1023 oxygen atoms. The number 6.02214179×1023 alone is called Avogadro's number (NA) or Avogadro's constant, after the 19th century scientist Amedeo Avogadro. read less

(1) The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as the amount of any substance that contains as many elementary entities (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of purecarbon-12 (12C), the isotope of carbon with relative atomic mass of exactly 12 by definition. This corresponds to the Avogadro constant, which has a value of 6.02214129(27)×1023 elementary entities of the substance. It is one of the base units in the International System of Units; it has the unit symbol mol and corresponds with the dimension symbol N. (2) The Avogadro number ( a constant ) is the number of constituent particles, usually atoms or molecules, that are contained in the amount of substance given by one mole. Thus it is the proportionality factor that relates the molar mass of a material to its mass. Avogadro's constant has the value 6.02214129(27)×1023 mol?1 in the International System of Units (SI). read less

1. A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12 (i.e., 6.023 X 1023). This involves the acceptance of two dictates -- the scale of atomic masses and the magnitude of the gram. 2. The number of atoms or molecules in a mole of a substance, approximately 6.0225 × 1023. Also called Avogadro constant. read less