science

2. Discovery of Tungsten
- In 1779 irish chemist deduced the existence
of a new element “Tungsten”from his analysis of the
mineral wolframite.Tungsten was isolated as tungistic
oxide(WO3)in 1781,in sweden,by carl W.
- Tungsten was isolated by brothers
in 1783 in spain by reduction of acidified
wolframite with charcoal.They produce the same acidic
metal oxide and even reduced it to tungsten metal by
heating with carbon.

4. 74
W
Tungsten
183.84
Atomic Number: 74
Atomic Weight: 183.84
Melting Point: 3695 K (3422°C or
6192°F)
Boiling Point: 5828 K (5555°C or
10031°F)
Density: 19.3 grams per cubic
centimeter
Phase at Room
Temperature: Solid
Element Classification: Metal
Period Number: 6 Group
Number: 6 Group Name: none
Estimated Crustal Abundance: 1.25
milligrams per kilogram
Estimated Oceanic Abundance: 1×10-
4 milligrams per liter
Number of Stable Isotopes: 2 (View
all isotope data)
Ionization Energy: 7.98 eV

5. Uses of Tungsten:
Tungsten has the highest melting point of all metallic elements and is
used to make filaments for incandescent light bulbs, fluorescent light
bulbs and television tubes. Tungsten expands at nearly the same rate as
borosilicate glass and is used to make metal to glass seals. Tungsten is
also used as a target for X-ray production, as heating elements in electric
furnaces and for parts of spacecraft and missiles which must withstand
high temperatures.
Tungsten is alloyed with steel to form tough metals that are stable at high
temperatures. Tungsten-steel alloys are used to make such things as high
speed cutting tools and rocket engine nozzles.

6. By far the most important use of tungsten is in making alloys. Tungsten
is used to increase the hardness, strength, elasticity (flexibility),
and tensile strength (ability to stretch) of steels. The metal is usually
prepared in one of two forms. Ferrotungsten is an alloy of iron and
tungsten. It usually contains about 70 to 80 percent tungsten.
Ferrotungsten is mixed with other metals and alloys (usually steel) to
make specialized alloys. Tungsten is also produced in powdered form. It
can then be added to other metals to make alloys.
About 90 percent of all tungsten alloys are used in mining, construction,
and electrical and metalworking machinery.
About 90 percent of all tungsten alloys are used in mining, construction,
and electrical and metal-working machinery. These alloys are used to
make high-speed tools; heating elements in furnaces; parts for aircraft
and spacecraft; equipment used in radio, television, and radar; rock
drills; metal-cutting tools; and similar equipment.
SOME EXAMPLES OF THINGS:

7. First, tungsten-containing steels were patented in 1858, leading to the first self-
hardening steels in 1868. High speed steels with tungsten additions up to 20%
were first exhibited at the World Exhibition in Paris in 1900, and revolutionized
engineering practice in the early 20th century. Such steels (Taylor- and White)
are still used today in practically every machine shop of the world.
The first tungsten light bulbs were patented in 1904, and rapidly replaced the
less efficient carbon filament lamps on the lighting market. Since then,
tungsten filaments have illuminated the world and have revolutionized
artificial lighting in general.
To produce drawing dies with diamond-like hardness but improved toughness
was the driving force for the development of cemented carbides in the 1920s.
At this time, no one, even the most optimistic, could imagine the enormous
breakthrough for this material in the tooling industry.

10. Physical properties
Tungsten is a hard brittle solid whose color ranges from steel-gray to nearly white. Its melting
point is the highest of any metal, 3,410°C (6,170°F) and its boiling point is about 5,900°C
(10,600°F). Its density is about 19.3 grams per cubic centimeter. Tungsten conducts electrical
current very well.
Chemical properties
Tungsten is a relatively inactive metal. It does not combine with oxygen at room temperatures. It
does corrode (rust) at temperatures above 400°C (700°F. It does not react very readily with acids,
although it does dissolve in nitric acid or aqua regia. Aqua regia is a mixture of hydrochloric and
nitric acids. It often reacts with materials that do not react with either acid separately.
Occurrence in nature
Tungsten never occurs as a free element in nature. Its most common ores are the minerals scheelite,
or calcium tungstate (CaWO 4 ) and wolframite, or iron manganese tungstate (Fe,MnWO 4 ). The
abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. It is one of
the more rare elements.
The largest producers of tungsten in the world are China, Russia, and Portugal. No tungsten was
mined in the United States in 1996. Detailed information about the production and use of tungsten in
the United States is not available. This information is withheld from the public to protect the
companies that produce and use tungsten.
In some parts or the world, tungsten is still called by another name, wolfram. This name comes from
the German expression Wolf rahm, or "wolf froth (foam)."