Lithium

Lithium is a chemical element with the symbol Li and atomic number 3. It is the lightest metal and the lightest solid element. A soft, silvery-white alkali metal, lithium tarnishes in air and reacts vigorously with water, forming lithium hydroxide and hydrogen gas.

Lithium is not found freely in nature; it occurs in minerals such as spodumene, petalite, and lepidolite, and in brine deposits. Major sources are evaporated brines in the Andean region and hard rock mining in Australia. Commercial production typically begins with concentration from brines or ore, followed by chemical processing and electrolysis to yield metallic lithium.

The element has several important applications. The most prominent are rechargeable lithium-ion and lithium-polymer batteries used in portable electronics and electric vehicles. Lithium metal is also used in certain high-strength alloys, ceramics, and glass. Lithium compounds, particularly lithium carbonate and lithium hydroxide, are used in ceramics and lubricants and have medical uses as mood stabilizers for bipolar disorder; treatment requires medical supervision because of potential side effects.

In nature, lithium has two stable isotopes, Li-6 and Li-7. Li-6 is used in some nuclear and fusion-related processes. Safety considerations include extreme reactivity with water; lithium is stored under oil or inert atmosphere to prevent contact with moisture. Environmental impacts arise from mining and brine extraction, with ongoing efforts to manage sustainability and supply security.