Avogadro constant of molecules in one gram-molecule of oxygen (exactly of oxygen, according to the definitions of the period), and this term is still widely used, especially in introductory works. The change in name to "Avogadro constant" ("N") came with the introduction of the mole as a base unit in the International System of Units (SI) in 1971, which regarded amount of substance as an independent dimension of measurement. With this recognition, the Avogadro constant was no longer a pure number, but had a unit of measurement, the reciprocal mole (mol). While it is rare to use units of amount of substance
Work (physics) "weight "lifted" through a height", which is based on the use of early steam engines to lift buckets of water out of flooded ore mines. According to Dugas, it is to Solomon of Caux "that we owe the term "work" in the sense that it is used in mechanics now". The SI unit of work is the joule (J). The SI unit of work is the joule (J), which is defined as the work expended by a force of one newton through a displacement of one metre. The dimensionally equivalent newton-metre (N⋅m) is sometimes used as the measuring unit for