Avogadro constant Avogadro constant In chemistry and physics, the Avogadro constant, named after scientist Amedeo Avogadro, 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 substance to the mass of a sample. The Avogadro constant, often designated with the symbol "N" or "L", has the value in the International System of Units (SI). (The parentheses there represent the degree of uncertainty.) Previous definitions of chemical quantity involved the Avogadro number, a historical term closely related to
Tog (unit) G in W/mK then a handy backronym for remembering what Tog means is "10/G", or "Ten Over G." Tog (unit) The tog is a measure of thermal insulance of a unit area, also known as thermal resistance. It is commonly used in the textile industry and often seen quoted on, for example, duvets and carpet underlay. The Shirley Institute in Manchester, England developed the tog as an easy-to-follow alternative to the SI unit of mK/W. The name comes from the informal word "togs" for 'clothing', which itself was probably derived from the word "toga", a Roman garment. The basic unit