Lithium (Li) is an alkali metal discovered in 1817 by Johann Arfvedson, given the atomic number 3. Its name comes from “lithos,” the Greek word for “stone,” because it was first discovered in a mineral source rather than a plant source. Like all alkali metals, lithium has one valence electron in its outer shell, making it highly reactive and not freely occurring in nature because it is extremely likely to donate that electron in ionic bonding. It is prone to spontaneously combust and can only be found in small quantities in igneous rocks and salts. Lithium has two naturally occurring isotopes, lithium-6 and lithium-7. The former is used in thermonuclear reactions and the latter, much more stable, isotope is used in medical research and controlling the pH of water coolant systems. Lithium is most commonly associated with batteries. Interestingly, it is believed to be one of the three elements, along with hydrogen and helium, that were created in the first three minutes of the universe. Hydrogen and helium are the two most abundant elements in the universe, but for reasons unknown lithium fails to even make the top ten – resulting in what is known as the “lithium problem.” There is only a third of the lithium in the universe than there should be and, in addition, lithium is never found in a pure form in nature and is difficult to isolate.
Lithium reacts with water, but not as much as sodium, and is the only alkali metal that reacts with nitrogen. It is the lightest and has the highest specific heat of the solid elements, but is extremely corrosive. Lithium is malleable with a density half that of water and it is a good conductor of electricity. Lithium batteries are lighter weight and conduct electricity better than other metals because of the exceptionally high energy density of the element. In addition to batteries, alloys made of lithium and aluminum, copper, manganese or cadmium are used in high performance aircraft manufacturing. It is also used in special glasses and ceramics like high powered telescopic lenses; lithium chloride is one of the most laparoscopic materials in existence thus far. Lithium stearate functions as an all-purpose and high temperature lubricant, while lithium carbonate is used as a mood-stabilizer, particularly for individuals suffering from bipolar disorder.
Lithium is silvery in color, but tarnishes in minutes when exposed to air, giving it a dull grey appearance. It was first discovered in the mineral petalite. Petalite itself was discovered at the end of the 18th century by José Bonifácio de Andrada e Silva. Several decades later lithium was found in the petalite. Arfvedson later discovered lithium in the minerals spodumene and lepidolite as well. Arfvedson and also C.G. Gmelin attempted to isolate lithium from lithium salts and failed, but found that lithium burns bright red. The following year W.T. Brande and Sir Humphrey Davy used electolysis of lithium oxide to isolate lithium.
Historically, lithium is extremely significant. Following World War II, production and synthesis of lithium as well as its isotopes dramatically increased. The element’s impressive and varied properties were quickly realized, along with the thermonuclear capabilities of lithium-6. In 1951, Sir John Crockcroft and Professor Ernest Walton received the Nobel Prize in Physics for the first successful nuclear transmutation in which lithium was transformed into helium. The lithium nuclei were rapidly bombarded with hydrogen nuclei and released helium nuclei as a result. Lithium is still relevant in science today, especially in areas of physics, astronomy and astrophysics, where many mysteries still remain. The lithium problem is deepened by the fact that natural particle collisions in space as well as super novae actually produce lithium, but no one is sure where all of the missing lithium is going.