Lithium (Li) is chemical element 3, an alkali metal in group 1, period 2 (PubChem).
- Atomic number: 3
- Symbol: Li
- Group: 1
- Period: 2
- Atomic mass: 7.0 u
- Electron configuration: [He]2s1
- Electronegativity (Pauling scale): 0.98
- Atomic radius (van der Waals): 182 pm
- Ionization energy: 5.392 eV
- Electron affinity: 0.618 eV
- Oxidation states: +1
- Standard state: Solid
- Melting point: 453.65 K
- Boiling point: 1615 K
- Density: 0.534 g/cm³
- Chemical group: Alkali metal
- Year discovered: 1817