Lithium Facts

Element cell for Lithium

Lithium Periodic Table Tile

Basic Lithium Facts

Name: Lithium

Atomic Number: 3

Element Symbol: Li

Group: 1

Period: 2

Block: s

Element Family: Alkali Metal

Atomic Mass: [6.938; 6.997] IUPAC guidelines
6.941 is commonly used for a single value

Electron Configuration: [He]2s1 (shorthand) or 1s22s1 (full)

Discovery: Johan August Arfwedson in 1817.
Arfwedson was analyzing petalite ore. When burned, it gave off a bright red flame. Further investigation showed it contained a substance that acted like an alkali metal but was lighter than sodium. He attempted to provide a pure sample of the metal by separating the metal using electrolysis, but was not successful. In 1821, English chemist William Brande produced a very small sample of pure lithium, but not enough to make any useful measurements. Lithium would not be produced in large quantities until 1855 by German chemist Robert Bunsen and British chemist Augustus Matthiessen.

Name Origin: lithos (Greek for “stone”) Arfwedson named his alkali metal after a stone to reflect its origin. Other alkali metals like sodium and potassium are commonly found in plants.

Common Isotopes:

Lithium is mostly comprised of two stable isotopes. Isotopes ranging from lithium-3 to lithium-12 have been produced in laboratory conditions.

Lithium-6 is a stable isotope of lithium containing three neutrons. 7.59% of natural lithium contains lithium-6.

Lithium-7 is the most common isotope. It contains 4 neutrons and accounts for 92.41% of all natural lithium.

Lithium Metal

Lithium metal with streaks of lithium oxide. Credit: Dennis S.K./Creative Commons

Physical Data

Density: 0.534 g/cm3

Melting Point: 453.65 K (180.50 ºC or 356.90 ºF)

Boiling Point: 1615 K (1342 ºC or 2448 ºF)

Critical Point: 3220 K at 67 MPa (extrapolated)

State at 20ºC: Solid

Heat of Fusion: 3.00 kJ/mol

Heat of Vaporization: 136 kJ/mol

Molar Heat Capacity: 24.860 J/mol·K

Lithium Atom

Electron configuration of a lithium atom.

Atomic Data

Atomic Radius: 1.52 Å (empirical)

Covalent Radius: 1.30 Å

Van der Waals Radius:  1.82 Å

Electron Affinity: 59.633 kJ/mol

Electronegativity: (Pauling scale): 0.98

1st Ionization Energy: 520.222 kJ/mol

2nd Ionization Energy: 7298.15 kJ/mol

3rd Ionization Energy: 11815.044 kJ/mol

Common Oxidation States: +1

Lithium Flame Test

Lithium flame test. Lithium burns with a vivid red flame. Credit: Herge/Public Domain

Fun Lithium Facts

  • Lithium is the lightest metal.
  • Lithium has the lowest density of any metal. Lithium can float on water.
  • Lithium is a shiny, soft metal which reacts violently with water forming a strong corrosive base. Lithium is often stored in oil for this reason.
  • Lithium burns with a bright red color. Lithium is added to fireworks to make red sparks.
  • Lithium is used extensively in rechargeable batteries. It is also used in many ceramics.
  • Lithium is used as an alloy additive to aluminum and magnesium to lower weight and improve strength.
  • Lithium is not found in its elemental form. Lithium is produced by electrolysis of ores containing lithium. The largest deposits of lithium containing ore are found in Chile.
  • The first man-made nuclear reaction was the transmutation of lithium into tritium.
  • Lithium carbonate is used in small doses to treat manic depression and bipolar disorders.
  • Lithium deuteride was an early consideration for thermonuclear bomb fuel. The lithium produces tritium which in turn fuses with the deuterium to release energy.
  • Like other alkali metals, lithium can be used to create soap. Lithium soap is used in many commercial lubricants.

Learn more about elements on the periodic table.

Lithium Facts
Last modified: May 19th, 2015 by Todd Helmenstine