Helium

nuclear number 2 Helium (Greek helios," solarisebathe"), symbol He, inert, colorless, odorless be adrift element. In group 18 of the periodic table, atomic second 2 is integrity of the statuesque gases. The atomic number of helium is 2. Pierre Janssen observed helium in the spectrum of the corona of the sun during an eclipse in 1868. briefly after it was identified as an element and named by the pharmacist Sir Edward Frankland and the British astronomer Sir Joseph Norman Lockyer. The gas was offset notion isolated from terrestrial sources in 1895 by the British pharmacist Sir William Ramsay, who discovered it in cleveite. In 1907 Sir Ernest Rutherford showed that alpha particles are the nuclei of helium atoms.

II PROPERTIES AND OCCURRENCE Helium has monatomic molecules, and is the lightest of all gases leave out hydrogen. Helium solidifies at -272.2° C; helium boils at -268.9° C. The atomic weight of helium is 4.0026. Helium, corresponding the other noble gases, is chemically inert. Its single electron eggshell is ...If you want to get a full essay, order it on our website: Ordercustompaper.com

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