Lithium
Li
Atomic Number: 3
Atomic Weight: 6.941
Melting Point: 453.65 K (180.50°C or 356.90°F)
Boiling Point: 1615 K (1342°C or 2448°F)
Density: 0.534 grams per cubic centimeter
Phase at Room Temperature: Solid
Element Classification: Metal
Period Number: 2
Group Number: 1
Group Name: Alkali Metal
History
Lithium was discovered in the mineral petalite (LiAl(Si2O5)2) by Johann August Arfvedson in 1817. It was first isolated by William Thomas Brande and Sir Humphrey Davy through the electrolysis of lithium oxide (Li2O). Today, larger amounts of the metal are obtained through the electrolysis of lithium chloride (LiCl). Lithium is not found free in nature and makes up only 0.0007% of the earth's crust.
Brief description
Lithium is a Group 1 (IA) element containing just a single valence electron (1s22s1). Group 1 elements are called "alkali metals". Lithium is a solid only about half as dense as water and lithium metal is the least dense metal. A freshly cut chunk of lithium is silvery, but tarnishes in a minute or so in air to give a grey surface. Its chemistry is dominated by its tendency to lose an electron to form Li+. It is the first element within the second period. Lithium is mixed (alloyed) with aluminium and magnesium for light-weight alloys, and is also used in batteries, some greases, some glasses, and in medicine.
The main lithium compound is the lithium hydroxide. It’s a white powder; the manufactured material is monohydrate lithium hydroxide. The carbonate can be used in the pottery industry and in medicine as an antidepressant. The bromine and the lithium chloride both form concentrated brine, which have the property of absorbing the humidity in a wide interval of temperature; these brines are used in the manufactured air conditioning systems.
The main industrial use of lithium is in lithium stearatum form, as lubricant grease’s thickener. Other important applications of lithium compounds are in pottery, specifically in porcelain glaze; as an additive to extend the life and performance of alkaline storage batteries and in autogenously welding and brass welding.
Alloys of the metal with aluminum, cadmium, copper, and manganese are used to make high performance aircraft parts. Metallic lithium will react with nitrogen, oxygen, and water vapor in air. Consequently, the lithium surface becomes coated with a mixture of lithium hydroxide (LiOH), lithium carbonate (Li2CO3), and lithium nitride (Li3N). Lithium hydroxide represents a potentially significant hazard because it is extremely corrosive. Special attention should be given to water organisms.