1-20号元素的性质及用(国外英文资料).doc

1-20号元素的性质及用(国外英文资料) hydrogen Hydrogen is the number one element in the periodic table, and the element name comes from Greek, meaning water element. Hydrogen was discovered in 1766 by British chemist cavendish, who called it a combustible air and proved that it was burning in the air to generate water. In 1787 the French chemist, Lavoisier, proved that hydrogen was a single substance and named it. Hydrogen is high in the earths crust, accounting for 15.4% of the atom, but only 1% of the weight. Hydrogen is the richest element in the universe. On earth, hydrogen is mainly used in water and organic matter. There are three isotopes: protium, deuterium, tritium. Hydrogen is normally a colorless, odorless gas; The gas molecules are composed of two atoms; Melting point of 259.14 ° C, the boiling point to 259.14 ° C, critical temperature 33.19 K, critical pressure 12.98 atmospheric pressure, gas density 0.0899 g/l; Water solubility 21.4 cm 3 / kg (0 ° C), slightly soluble in organic solvents. At room temperature, hydrogen is less active, but can be activated by suitable catalysts. At high temperatures, hydrogen is highly active. In addition to the rare gas elements, almost all elements can produce compounds with hydrogen. The non-metallic hydride is usually called a certain hydrogen, such as halogenated hydrogen and hydrogen sulfide, etc. The metal elements are called metal hydride, such as hydrogenated lithium and calcium hydrogenated. Hydrogen is an important industrial raw material and a future source of energy. -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Edit the Helium. The element symbol He, atomic number 2, atomic weight 4.002602, is a kind of rare gas. The element name comes from Greek, meaning the sun. In 1868 someone used a spectroscope to look at the surface of the sun