Lithium Facts: Li or Element 3

Lithium is the first metal you encounter on the periodic table. Here are important facts about this element.

Lithium Basic Facts

• Atomic Number: 3
• Symbol: Li
• Atomic Weight: [6.938; 6.997]
  Reference: IUPAC 2009
• Discovery: 1817, Arfvedson (Sweden)
• Electron Configuration: [He]2s¹
• Word Origin Greek: lithos, stone
• Element Classification: Alkali Metal

Lithium Properties

Lithium has a melting point of 180.54 C, a boiling point of 1342 C, a specific gravity of 0.534 (20 C), and a valence of 1. It is the lightest of the metals, with a density approximately half that of water. Under ordinary conditions, lithium is the least dense of the solid elements. It has the highest specific heat of any solid element. Metallic lithium is silvery in appearance. It reacts with water, but not as vigorously as does sodium. Lithium imparts a crimson color to flame, although the metal itself burns a bright white. Lithium is corrosive and requires special handling. Elemental lithium is extremely flammable.

Lithium Uses

Lithium is used in heat transfer applications. It is used as an alloying agent, in synthesizing organic compounds, and is added to glasses and ceramics. Its high electrochemical potential makes it useful for battery anodes. Lithium chloride and lithium bromide are highly hygroscopic, so they are used as drying agents. Lithium stearate is used as a high-temperature lubricant. Lithium has medical applications as well.

Lithium Sources

Lithium does not occur free in nature. It is found in small amounts in practically all igneous rocks and in the waters of mineral springs. The minerals that contain lithium include lepidolite, petalite, amblygonite, and spodumene. Lithium metal is produced electrolytically from the fused chloride.

Lithium Physical Data

• Density (g/cc): 0.534
• Appearance: soft, silvery-white metal
• Isotopes: 8 isotopes [Li-4 to Li-11]. Li-6 (7.59% abundance) and Li-7 (92.41% abundance) are both stable.
• Atomic Radius (pm): 155
• Atomic Volume (cc/mol): 13.1
• Covalent Radius (pm): 163
• Ionic Radius: 68 (+1e)
• Specific Heat (@20°C J/g mol): 3.489
• Fusion Heat (kJ/mol): 2.89
• Evaporation Heat (kJ/mol): 148
• Debye Temperature (°K): 400.00
• Pauling Negativity Number: 0.98
• First Ionizing Energy (kJ/mol): 519.9
• Oxidation States: 1
• Lattice Structure: Body-Centered Cubic
• Lattice Constant (Å): 3.490
• Magnetic Ordering: paramagnetic
• Electrical Resistivity (20°C): 92.8 nΩ·m
• Thermal Conductivity (300 K): 84.8 W·m−1·K−1
• Thermal Expansion (25°C): 46 µm·m−1·K−1
• Speed of Sound (thin rod) (20°C): 6000 m/s
• Young's Modulus: 4.9 GPa
• Shear Modulus: 4.2 GPa
• Bulk Modulus: 11 GPa
• Mohs Hardness: 0.6
• CAS Registry Number: 7439-93-2

Lithium Trivia

• Lithium is used extensively in rechargeable battery technology.
• Lithium is the only alkali metal that reacts with nitrogen.
• Lithium burns red in a flame test.
• Lithium was first discovered in the mineral petalite (LiAlSi₄O₁₀).
• Lithium is used to create the hydrogen isotope tritium through bombardment of neutrons.

Sources

• Los Alamos National Laboratory (2001)
• IUPAC 2009
• Crescent Chemical Company (2001)
• Lange's Handbook of Chemistry (1952)