Page 25 - Curriculum Visions Dynamic Book

At see Astatine, Au see Gold, B see Boron Barium (Ba)
Element 56. It is one of the alkaline earth metals in group 2 in the Periodic Table.
It is a silvery-white, lead-like element when freshly cut but slightly heavier than lead.The metal reacts with air quickly and tarnishes rapidly. It is very reactive with water and alcohol.
Key facts...
Name: barium
Symbol: Ba
Atomic number: 56
Atomic weight: 137.34
Position in Periodic Table: group 2 (2) (alkaline
earth metal); period 6
State at room temperature: solid
Colour: silvery-white
Density of solid: 3.51 g/cc
Melting point: 725°C
Boiling point: 1,640°C
Origin of name: from the Greek word barys,
meaning heavy
Shell pattern of electrons: 2–8–18–18–8–2
Barium is isolated by electrolysis of molten barium chloride. Barium collects at the cathode.
Barium sulphate makes a white filler for rubber and paper. It also helps make a brilliant white colouring substance for paint. Barium is used in glass- making. Barium nitrate makes the green colour in signal flares and
in fireworks. Barium carbonate is a rodent poison.
Geology
 Brown–green barium flame
Discovery
Barium was discovered in England in 1808 by Sir Humphry Davy by electrolysis of a molten barium oxide.
Technology
The element is used in metallurgy, and its compounds appear in fireworks, petroleum mining and radiology.
Barium is too reactive
to form native deposits.
It is mainly found as
the mineral barite. Barite
is easily distinguished from other white minerals by its weight.
Biology
Barium is not normally a part of living things. Barium sulphate is insoluble and so can be used for tracing purposes in medicine (X-rays can trace a ‘barium meal’). Other barium compounds
are poisonous.
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