Atomic Weight: 1.00794
Element Type: Non-Metal
Crystal Structure: Hexagonal
Melting Point: -259.34°C = -434.812°F
= 13.81 K
Boiling Point: -353.87°C = -604.966°F
= -80.72 K
Critical Temp: -240.18°C = -400.324°F
= 32.97 K
Atomic Radius: 0.79 Å (Å
= Angstrom = 10-10 m)
Covalent Radius: 0.32 Å
(Gr. hydro, water, and genes, forming) Hydrogen was prepared
many years before it was recognized as a distinct substance
by Cavendish in 1776.
Named by Lavoisier, hydrogen is the most abundant of all
elements in the universe. The heavier elements were originally
made from Hydrogen or from other elements that wereoriginally
made from Hydrogen.
Hydrogen occurs in the free state in volcanic gases and
some natural gases. Hydrogen is prepared by steam on heated
carbon, decomposition of certain hydrocarbons with heat,
action of sodium or potassium hydroxide on aluminum electrolysis
of water, or displacement from acids by certain metals.Hydrogen
is the most abundant element in the universe although it
is not present in our atmosphere.
Hydrogen is important in the proton-proton
reaction and carbon-nitrogen cycle. Liquid hydrogen is used
in cryogenics and in the study of superconductivity. Great
quantities are used for the fixation of nitrogen from the
air in the Haber ammonia process. Hydrogen is use in welding,
for the hydrogenation of fats and oils, in methanol production,
in hydrodealkylation, hydrocracking, and hydrodesulfurization.
Other applications include producing rocket fuel, filling
balloons, making fuel cells, producing hydrochloric acid,
and reducing metallic ores. Deuterium is used as a moderator
to slow down neutrons and as a tracer. Tritium is used in
the production of the hydrogen (fusion) bomb. Tritium is
also used in making luminous paints and as a tracer.