| |
| | SI - RSCI, The Science Classification Index (Site not responding. Last check: 2007-10-23) |
 | | It is preferable to keep the symbol in upright Roman type (for example, m for metres, L for litres), so as to differentiate from mathematical and physical variables (for example, m for mass, l for length). |
 | | The unit of mass is equal to the mass of the international prototype kilogram (a platinum-iridium cylinder) kept at the Bureau International des Poids et Mesures (BIPM), Sèvres, Paris (1st CGPM (1889), CR 34-38). |
 | | Note that the kilogram is the only base unit with a prefix; the gram is defined as a derived unit, equal to 1/1 000 of a kilogram; prefixes such as mega are applied to the gram, not the kg; e.g. |
| www.scienceindex.org /SI.html (2220 words) |
|