The 6th group elements of Cr-group in periodic table.
The name is originated from the molybdenite of the
ore MoS2. In ancient Greek, molybdos meant lead,
especially, a galena out of lead ore was called to mo
lybdenum, in latter, black lead and Molybdenite were
included in this category of molybdenum. But when
Swedish scientist K.W. Scheele found molybdenum at
1778, these were separated into other materials and
Molybdenite has been called to as is
Elementary Symbol Mo Electronegativity, Pauling 2.16
Atomic Number 42 State at RT Solid, Metal
Atomic Weight 95.94 Melting Poin(”É) 2662”¾10
Oxidation States 2,3,4,5,6 Boiling Point(Ӄ) 4800
It exists relatively wide extents in the earth but its amount is not so much. Its
Clarkes No. is 0.0013(the 42nd), contained in earth's crust as the same amount of
lead, and main ore is Molybdenite. It is a biophile element, so it is always contained
in animal and plant though it is little amount, as well as sea. Main producing center is
US, occupies about 70% of the world production, and 2/3 of it are produced from
Climax Mine of CO. It is also produced in Canada”¤Russia”¤Chile”¤China”¤Austrailia.
Reduced one is gray powder, and sintered or melted one is polished silver-white
metal. It has electric conductivity and ductility, and possible to casting and rolling. It
has been known the metal with high melting point together with tungsten, similar to
carbon in high temperature since its vapor pressure is low, and also possible to forg
ing. It has very strong mechanical power in all temperature from ultimately low to
high temperature through RT. Electronic conductivity is 34% of that of silver, and react
with oxygen, chloride, bromine, carbon, silicon, and iodine in high temperature. More
over it composes the fluoride with fluorine in low temperature. Atomic value for
chemical is 2, 3, 4, 5, and 6, and 6th is most stable out of them. It is not dissolved
in hydrochloric acid and weak sulphuric acid but dissolved in strong sulphuric acid,
nitric acid, and aqua regia, furthermore it vigorously dissolved in the mixture of
hydrogen fluoride and sulphuric aacid.