Page 48 - Curriculum Visions Dynamic Book

W see Tungsten Xenon (Xe)
Element 54. Xenon is one of the noble gases, group 8 in the Periodic Table.
It is a very rare, heavy gas that is colourless, odourless and tasteless. Only one part of air in twenty million is xenon. However, it is more plentiful in some mineral springs. It also exists in the Martian atmosphere. It is recovered commercially by liquefying air.
Xenon is one of the ‘inert’ gases. It is remarkably unreactive and mainly only forms compounds with fluorine, which is the most reactive non-metal known. Xenon compounds with metals are known as perxenates.
Some of the rare compounds that have been produced in the laboratory include compounds such as sodium perxenate, xenon difluoride, xenon tetrafluoride and xenon hexafluoride. The perxenates are used as
oxidising agents in
laboratories.
Discovery
Xenon was discovered in 1898 by the British chemists Sir William Ramsay and Morris W.Travers as they evaporated liquid air to find out what it was made of.
Technology
When xenon is excited by an electric charge in a vacuum, it gives off a blue glow, which is a source of strobe lights, high-speed photography bulbs and bulbs that kill bacteria.
Geology
Xenon makes up a tiny part of the air (0.01 part per million). It is four and a half times as heavy as air.
Biology
Xenon is not found in living things. The element
itself is not harmful, but
its compounds are very toxic because the only compounds
it makes are with extremely
powerful oxidising agents.
Key facts...
Name: xenon
Symbol: Xe
Atomic number: 54
Atomic weight: 131.29
Position in Periodic Table: group 8 (18)
(noble gases); period 5
State at room temperature: gas
Colour: colourless
Density of gas at 20°C: 5.49 g/l
Melting point: –111.9°C
Boiling point: –107.1°C
Origin of name: from the Greek word xenos,
meaning stranger
Shell pattern of electrons: 2–8–18–18–8
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