Hydrogen.
From Greek hydros (water) and genius (generator). Name given by Lavoisier. Discovered in 1766 by Henry Cavendish, who called it flammable air and proved that water resulted from the combination of this element with oxygen.
Most abundant element in the Universe, in which it participates with 90% by weight. In the Earth's atmosphere it is found free in small quantities (only 0.5 ppm in volume). In the combined state, it appears mainly in the form of water. It is present in the composition of practically all organic compounds. In the earth's crust, it is the ninth most abundant element (0.88% by weight).
Applications:
H 2 Combustible gas (hydrogen torches). Manufacture of ammonia (NH3), methyl alcohol (CH3OH) and many other compounds of great industrial importance. Margarine manufacture (hydrogenation of vegetable oils).
As the hydrogen compounds are very numerous, their main applications have been mentioned in those of the element (s) with which it is combined. Example: the applications of NH 3 were mentioned in those of nitrogen compounds.
Periodic Properties Table:
Atomic Mass: 1,0079 u
Density (25 ºC): 0.090 g / L (CNTP)
Ionization Energy: 1311 kJ / mol
Melting Point: -259 ºC
Boiling Point: -252 ºC
Atomic Radius: 37 pm
Electronegativity: 2.20
