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 ensure competence, fair dealing and high integrity. The Australian Au-Pair Families Association (AAPFA) is a not-for-profit organisation and members are Australian host families. AAPFA supports self-regulation in the Au pair industry and provides information and guidance to Au-Pair families based on international hosting standards and ethics. Au pair agencies in China sent young Chinese to the west to work as au pairs abroad, particularly for families who had adopted babies from China, to help them learn Chinese. In addition, China's rising middle class and economic growth have led to a growing demand for au pairs. This helps create opportunities to