History of the metric system levels of the krypton 86 atom as the new standard for the metre. The standard metre artefact was retired. In 1960, Giorgi's proposals were adopted as the basis of the "Système International d'Unités" (International System of Units), the SI. This initial definition of the SI included six base units, the metre, kilogram, second, ampere, degree Kelvin and candela, and sixteen coherent derived units. The evolution of the SI after its publication in 1960 has seen the addition of a seventh base unit, the "mole", and six more derived units, the "pascal" for pressure, the "gray", "sievert" and "becquerel" for radiation,
Orders of magnitude (mass) Orders of magnitude (mass) To help compare different orders of magnitude, the following lists describe various mass levels between 10 kg and 10 kg. The table below is based on the kilogram (kg), the base unit of mass in the International System of Units (SI). The kilogram is the only standard unit to include an SI prefix ("kilo-") as part of its name. The "gram" (10 kg) is an SI derived unit of mass. However, the "names" of all SI mass units are based on "gram", rather than on "kilogram"; thus 10 kg is a "megagram" (10 g), not a