Use of SI units & prefixes
A brief history of SI units and how they are now defined is followed by the seven basic units. This leads on to the derived SI units used in chemistry and the use of prefixes for small and large values. An engraving by an unknown artist showing the creation of a new one metre alloy standard reference rod at the Conservatoire des Arts et Métiers in Paris in 1874. The origin of Le Système International d'Unités or...