Zinc is a metallic chemical element; it has the symbol Zn
and atomic number 30. It is the first element of group 12 of the periodic
table. It’s the 24th most abundant element in the Earth's crust and has five
stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc
sulfide mineral. The largest mineable amounts are found in Australia, Asia, and
the United States.
Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC.
Zinc is an essential mineral of "exceptional biologic and
public health importance". Zinc
deficiency affects about two billion people in the developing world and is associated
with many diseases. In children it
causes growth retardation, delayed sexual maturation, infection susceptibility,
and diarrhoea, contributing to the death of about 800,000 children worldwide
per year.
The metal is most commonly used as an anti-corrosion agent. Galvanization, which is the coating of iron or
steel to protect the metals against corrosion, is the most familiar form of
using zinc in this way. Zinc is more
reactive than iron or steel and thus will attract almost all local oxidation
until it completely corrodes away. A
protective surface layer of oxide and carbonate forms as the zinc corrodes. This protection lasts even after the zinc
layer is scratched but degrades through time as the zinc corrodes away. The zinc is applied electrochemically or as
molten zinc by hot-dip galvanizing or spraying. Galvanization is used on
chain-link fencing, guard rails, suspension bridges, light posts, metal roofs,
heat exchangers, and car bodies.
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| Zinc Oxide used in paint pigments |
Zinc is useful for the human body and helps speed up the healing process after an
injury. It is also suspected of being
beneficial to the body's immune system. Indeed, zinc deficiency may have
effects on virtually all parts of the human immune system.
For more information visit:-
http://www.theguardian.com/science/punctuated-equilibrium/2011/sep/23/1?guni=Article:in%20body%20link
http://en.wikipedia.org/wiki/Zinc
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