What is Material Quantity?
Material quantity has to do with how much of something there is in a given place. Colloquially, it is measured using pounds or kilograms, but many scientists prefer mass, which more objectively describes the material quantity in a given sample. Because mass is usually correlated to weight in everyday situations, kilograms are also used to measure mass. When chemists refer to the material quantity of particles in a sample, they often use moles, a quantity that refers to roughly 6 x 1023 units of something, usually atoms or molecules. The large number is known as Avogadro’s number or Avogodro’s constant, named after the Italian scientist Amedeo Avogadro, who realized, in the early nineteenth century, that the volume of a gas is proportional to the material quantity of particles within the gas. Avogodro’s number is defined as the number of atoms in exactly 12 grams of carbon. As long as a system does not lose or gain atoms, either though exchange with the outside or nuclear fission/fusion
