3
Li
Lithium
6.94
Lithium (Li)
Alkali MetalGroup 1Period 2s-block-block
Lithium (from Greek:λίθος lithos, "stone") is a chemical element with the symbol Li and atomic number 3. It is a soft, silver-white metal belonging to the alkali metal group of chemical elements. Under standard conditions it is the lightest metal and the least dense solid element.
Latin name: Lithium
Atomic Number
3
Atomic Mass
6.94 g/mol
Phase (STP)
Solid
Electron Config.
[He] 2s¹
General
SymbolLi
Atomic Number3
Atomic Mass6.94 g/mol
CategoryAlkali Metal
Group1
Period2
Blocks-block
Electron Configuration[He] 2s¹
Valence Electrons1
ColourSilvery-white
Appearancesilvery-white
CAS NumberCAS7439-93-2
Physical Properties
Phase (STP)Solid
Density0.534 g/cm³
Melting Point180.50°C · 356.90°F · 453.65 K
Boiling Point1329.85°C · 2425.73°F · 1603.00 K
Atomic Properties
Atomic Radius167 pm
Covalent Radius128 pm
Electronegativity0.98 Pauling
Ionization Energy520 kJ/mol
Electron Affinity59.6 kJ/mol
Oxidation States+1
Ion ChargeLi⁺
Thermodynamic
Molar Heat24.86 J/(mol·K)
Thermal Conductivity85 W/(m·K)
Electromagnetic
Electrical TypeConductor
Crystal Structure
Crystal StructureBody-centered cubic
Mechanical Properties
Mohs Hardness0.6
Abundance
In Universe0.00005999999999999999%
In Sun0.0000006%
In Earth's Crust0.2000%
In Oceans0.0018%
In Humans0.00003%
In Meteorites0.0170%
Discovery & History
Discovery Year1817
Discovered ByJohan August Arfwedson
Isotopes of Lithium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Li-6 | 7.59% | Stable | — |
| Li-7 | 92.41% | Stable | — |