Chemical element of metals. Cu comes from Cuprum, Fe comes from Ferrum, Ag from Argentum. The symbols were not followed by a period (full stop) as with abbreviations. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English. For example, sodium has the chemical symbol 'Na' after the Latin "natrium". The same applies to "W" (wolfram) for tungsten, "Fe" (ferrum) for iron, "Hg" (hydrargyrum) for mercury, "Sn" (stannum) for tin, "K" (kalium) for potassium, "Au" (aurum) for gold, "Ag" (argentum) for silver, "Pb" (plumbum) for lead, "Cu" (cuprum) for copper, and
Au pair sites. Commercial au pair agencies do not charge a placement fee to incoming au pairs. The Au-Pair Society e.V. is a member of the International Au Pair Association (IAPA) and is also in a committee ECAPS (European Committee for Au-Pair Standards) where members of National Organisation from several European countries have defined new Standards for Au-Pair programme in Europe. Non-EU citizens no older than 24 can become au pairs through a German agency. Americans and Canadians do not need to apply for a residence and work permit before leaving their home countries; however, it is a general requirement that au