Mercury:
|
Atomic number
|
80
|
|
Symbol
|
Hg
|
|
Atomic weight
|
200.59
|
|
Discovery
|
Known to the ancient Hindus and Chinese. Mercury has been found in Egyptian tombs dating to 1500 B.C. The Greeks used mercury in ointments. The roman used mercury in cosmetics.
|
|
Electronic configuration
|
5d10
|
|
Word origin
|
Named for the planet Mercury Hg is the symbol for "Hydrargyrum" which means liquid silver.
|
|
Melting point
|
-38.8420C
|
|
Boiling point
|
356.580C
|
|
Specific gravity
|
13.546 (200C)
|
|
Electrical resistivity
|
0.95*10-6 ohm-m
|
Properties:
1. Mercury is one of the few elements that are liquid at ordinary room temperatures.
2. It is the heaviest known elemental liquid.
3. Mercury is a silvery white metal.
4. It is a relatively poor conductor of heat, but a fair conductor of electricity.
5. It readily forms alloy with other metals, called amalgams.
6. Mercury and its compounds absorbed across unbroken skin through the respiratory tract. It acts as a cumulative poison.
Uses: Mercury is amalgamated with gold to facilitate the recovery of gold from its ores. Mercury is used to make thermometers, diffusion pumps, barometer, mercury vapour lamps, mercury switches, pesticides, batteries, dental preparations, antifouling paints, pigments and catalyst. It is used in mercury are rectifier and gas filled tubes. It is also used as liquid contact material in electrical switches etc.
Sources: Mercury rarely occurs freely in nature. Its chief one is cinnabar, HgS. Mercury is obtained from cinnabar by heating the cinnabar in air and condensing the vapour.