Lithium

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Lithium

This is lithium.

Symbol Li
Atomic number 3
Atomic mass 6.941 amu

Lithium is the lightest of all metals. Discovered in 1817, this soft, silvery-white metal reacts readily with water and air. It cannot exist in nature in its pure form. Lithium is refined from minerals and ores that contain lithium compounds that do not react readily with any of the normal conditions of nature. One of these minerals is spodumene [LiAl(Si2O6)].

Distinguishing properties

Lithium metal is produced on a commercial scale by the electrolysis of molten lithium chloride (LiCl). Lithium metal must be kept in a dry, oxygen-free environment throughout the production process. This requirement adds significantly to the cost of this metal. Lithium metal must be packed, shipped, and stored in oxygen- and water-free environment. This is usually accomplished by packing the metal in a container of oil, kerosene, or other nonreactive liquid. Pictured to the right is lithium immersed in inert oil.

Usage

Some uses of lithium metal include:

  • alloying with magnesium and aluminum to form a strong, low density material for armor and aerospace parts.
  • rechargeable lithium batteries which are light-weight and are capable of producing high current densities. One possible use of lithium batteries is in electric cars.

Common compounds

Many compounds of lithium have valuable applications.

  • Li2CO3:
    • as a flux in porecelain enamel formulations,
    • in the making of toughened glasses,
    • in aluminum production to lower the melting temperature of the molten salt electrolytic cell,
    • in medicine for the treatment of manic depression.
  • LiOH:
    • as an absorber for CO2 in closed environments such as spacecraft,
    • in the production of lithium stearate which finds extensive used in the manufacture of specialty greases (i.e. high resistance to water, and useful at low temperatures of - 20°C.)
  • LiH: used in the production of H2 in meteorological applications.
  • LiAlH4: used as a selective reducing agent in synthetic organic chemistry.

See also

Periodic table of the elements