Helium

Helium DISCOVERY: A French astronomer, Pierre-Jules-C?sar Janssen (1824-1907), first obtained foregone conclusion for the existence of atomic number 2 during the solar loom of 1868 in India when he detected a new icteric line (587.49 nm) in the solar spectrum very close to the chicken sodium D-line. It was non possible to produce this line in the laboratory. Sir Norman Lockyer (1836-1920), an face astronomer, recognised that no known element at that era gave this line and named the element helium for the solarize. For many old age helium was regarded as an element that might exist on the sun although it was unknown on the Earth. Spectroscopists at the time doubted the results concerning helium. nonetheless the claims initiated a search for the new element on artificial satellite earth. In 1895, Sir William Ramsay detect helium after treating cleveite, a uracil mineral, with mineral acids. Ramsey sent samples of the gas to Sir William Crookes and Sir Norman L ockyer who identify helium. It was discovered independ...If you want to get a full essay, put in it on our website: OrderEssay.net

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