Lithium

Category: alkali metal Atomic number: 3 Colour: silvery white Melting point: 181°C (358°F) Boiling point: 1,342°C (2,448°F) First identified: 1817

Scientists believe that the only element initially created in the Big Bang other than hydrogen and helium was the metal lithium, albeit in much smaller quantities. Lithium was first found in 1800 in petalite, a pale or transparent ore that can be formed into gemstones, but it was only in 1817 that the chemist Johan August Arfwedson realized that this ore contained a previously unknown element. He named it after the Greek word lithos, which means stone, because it had been found in an ore, whereas other alkali metals such as potassium and sodium were first clearly identified in organic matter, such as plant ashes and animal blood. In 1821, William Thomas Brande used electrolysis of lithium oxide to isolate pure lithium. It is soft and silvery, with the lowest density of any metal, and has a violent reaction with water.

Lithium doesn’t naturally occur as a metal on Earth, as it is so reactive that the pure form has to be kept under a protective oil to protect it from corrosion. Instead, it is found in trace amounts in various igneous rocks and dissolved in the water of mineral springs.

The Strange Case of 7 Up

Most people know that Coca-Cola originally contained cocaine, but did you know that the original version of 7 Up included lithium citrate, which can be used to medicate mood swings? The Howdy Corporation, founded by Charles Leiper Grigg, launched a new soft drink in 1920, which was called ‘Bib-Label Lithiated Lemon-Lime Soda’. The name was eventually changed to 7 Up but it became illegal for beverage manufacturers to include lithium in their products in 1948.

The physician, Soranus of Ephesus, may have been unknowingly using lithium as a medicine in the second century when he prescribed the alkaline water from a local spring (which is now known to contain lithium) for mania and melancholia. Lithium carbonate has been used for medicinal purposes since the nineteenth century, with varying success; in particular, since the 1940s, it has been used as a treatment for bipolar disorder, in spite of some controversy over its side effects and potential toxicity.

Lithium can also be used in alloys with aluminium and magnesium, making them stronger and lighter – these are used in aircraft, bicycles and trains, where a lighter metal allows for greater speed. And a lithium compound is used for the cathodes in lithium batteries, which are longer lasting than most standard battery types.