Page 39 - Curriculum Visions Dynamic Book

Tl see Thallium Tungsten (W)
Element 74.Tungsten was formerly called wolfram. It is a white to greyish metal belonging to the transition metals in the Periodic Table.
It is the strongest metal known at high temperatures, and it also has the highest melting point of all metals.Tungsten oxidises in air, but the thin oxide film that forms then protects it from further corrosion. It is resistant to attack by acids. It has about the same coefficient of expansion as laboratory glass.
Key facts...
Symbol: tungsten
Symbol: W
Atomic number: 74
Atomic weight: 183.8
Position in Periodic Table: transition metal,
group (6) (chromium group); period 6 State at room temperature: solid Colour: greyish-white
Density of solid: 19.3 g/cc
Melting point: 3,410°C
Boiling point: 5,660°C
Origin of name: from the Swedish words
tung (heavy) and sten (stone). The symbol W is from wolfram, named after the tungsten mineral wolframite.
Shell pattern of electrons: 2–8–18–32–12–2
Discovery
It was discovered in 1783 by the Spanish chemist brothers Juan José and Fausto Elhuyar.
Technology
It is used as an alloy with steel and in the filaments of light bulbs, as well as for the elements in electric furnaces.As tungsten
carbide it is used in drill bits. It can be used with glass in the laboratory because it expands at about the same rate as laboratory glassware.
Tungsten salts are part of fluorescent lighting and hide tanning.
Geology
Tungsten is not found as the native element.The main mineral containing tungsten is wolframite (iron– manganese tungstate,
FeMnWO4).
Biology
Tungsten is an important trace element.
 The filament in a household light bulb is
made of tungsten, which
can glow white hot without burning.About a metre of tungsten wire is coiled up like a spring to make the filament in a standard light bulb.
39