The lithium atom is the smallest of the metal atoms in the periodic table. It is the lightest and most reactive of the alkali metals, it floats on water but strongly reacts with water yielding lithium hydroxide and hydrogen gas. Lithium is a soft silver-grey metal, yet when combined with metals such as magnesium, it forms a very strong alloy. Lithium is also highly reactive, reacting with water, oxygen, carbon dioxide and nitrogen at room temperature. In contrast, lithium compounds, are very stable.
|Atomic Number:||3||Atomic Radius:||182 pm (Van der Waals)|
|Atomic Symbol:||Li||Melting Point:||180.5 °C / 356.9 °F / 453.65 K|
|Atomic Weight:||6.94||Boiling Point:||1330 °C / 2448 °F / 1603 K|
|Electron Configuration:||[He]2s||Oxidation States:||+1 (a strongly basic oxide)|
|Hardness (Mohs’ scale)||0.6||Density at 20 °C in g/cm3||0.53|
|Standard Electrode Potential in V||-3.045||Electrical conductivity in 10^6 (Ohm.cm)||0.108|
|Specific heat in J/(g.K)||3.582||Ionization potential in eV||5.392|
Lithium was first identified in 1817, one of several to be found during a golden age of element discovery. In 1800, the Brazilian scientist José Bonefácio de Andrada e Silva (1763-1838) discovered two new minerals on the Swedish island of Utö which were called petalite and spodumene. But it was only in 1817 that the Swedish scientist Johan August Arfvedson (1792-1841) who worked in the laboratories of the renowned chemist and professor of medicine and pharmacy, Baron Jöns Jacob Berzelius (1779-1848), was able to solve the problems regarding inexplicable differences in the analyses of these minerals. He isolated a sulphate which did not contain any of the known alkali or alkaline earth metals. The new element he found was finally named “lithium”, derived from the Greek word “lithos” for stone. With the discovery of this new element, another gap in the periodic table was filled.
Due to lithium’s high reactivity, metallic lithium is not found as such in nature. Traces of this element are present in nearly all minerals, brines, clays and sea water. The crust of earth contains an average of about 20 parts per million (ppm) or 0.0020% while sea water typically contains 0.18ppm Li (0.000018%).