Li
Lithium
Element 3 · Alkali metal
Lithium (Li)
Lithium is the lightest metal and the least dense solid element. Soft and silvery, it powers most of the world’s rechargeable batteries.
- Alkali metal
- Period 2
- Group 1
- s-block
- solid at room temperature
Key properties
- Atomic mass
- 7
- u
- Electron configuration
- [He] 2s1
- Melting point
- 180.5 °C
- 453.65 K
- Boiling point
- 1,341.9 °C
- 1,615 K
- Density
- 0.534 g/cm³
- Electronegativity
- 0.98
- Pauling
- Atomic radius
- 182 pm
- van der Waals
- 1st ionisation energy
- 5.392 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about lithium
- 01
Lithium is so light that it floats on water — and on oil, which is how it is often stored.
- 02
It is one of only three elements made in the Big Bang, alongside hydrogen and helium.
- 03
Lithium salts have been used since 1949 as a mood stabiliser to treat bipolar disorder.
Applications
What is lithium used for?
- Lithium-ion batteries
- Psychiatric medication
- Heat-resistant glass and ceramics
- Lubricating greases
History
Discovery & name origin
Discovered by
Year
Where
Sweden
Name origin
Greek lithos, “stone” — it was discovered in a mineral, unlike sodium and potassium found in plant ash.
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 3
- Atomic mass
- 7 u
- Group
- 1
- Period
- 2
- Block
- s-block
- Electron configuration
- [He] 2s1
- Full configuration
- 1s2 2s1
- Electrons per shell
- 2, 1
- Electronegativity (Pauling)
- 0.98
- Electron affinity
- 0.618 eV
- Atomic radius (van der Waals)
- 182 pm
- Stable isotopes
- 2
Oxidation states
Highlighted: common oxidation states (+1).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st520.2
- 2nd7,298.1
- 3rd11,815
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 453.65 K · 180.5 °C · 356.9 °F
- Boiling point
- 1,615 K · 1,341.9 °C · 2,447.3 °F
- Density
- 0.534 g/cm³
- Molar heat capacity
- 24.86 J/(mol·K)
- Appearance
- Silvery-white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Lithium questions
What is Li on the periodic table?
Li is the symbol for lithium, element 3 on the periodic table. It sits in group 1, period 2, in the alkali metal category, and has an atomic mass of 7.
What is the atomic number of lithium?
Lithium has atomic number 3, so every lithium atom has 3 protons in its nucleus. Its symbol is Li and its atomic mass is 7.
Who discovered lithium?
Lithium was discovered by Johan August Arfwedson in 1817 (Sweden). The name comes from Greek lithos, “stone” — it was discovered in a mineral, unlike sodium and potassium found in plant ash.
What is lithium used for?
Lithium is used for: lithium-ion batteries; psychiatric medication; heat-resistant glass and ceramics; lubricating greases.
Is lithium a metal?
Yes. Lithium is a alkali metal, one of the metallic elements.
What is the electron configuration of lithium?
The electron configuration of lithium is [He] 2s1. Its 3 electrons are arranged in shells as 2, 1.