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 Pairs’ community is the visa requirement for foreigners. Entering Turkey without a valid visa is impossible for Au Pairs – and to apply for a visa any potential Au Pair needs both an Au Pair contract and an invitation letter, what significantly reduces the number of people willing to make an effort and go through such a complicated application process. The tradition of au pairing is well established in Austria, and prospective au pairs are served by several agencies that are accustomed to dealing with direct applications from foreigners. Agencies often charge their au pairs a fee equivalent to a