Lithium (Li): Electron Configuration, Properties and Uses
Lithium (Li): Electron Configuration, Properties and Uses
Electron configuration [He] 2s1 · group 1 · period 2 · Ar 6.94
Lithium data
- Atomic number
- 3
- Relative atomic mass
- 6.94
- Group
- 1
- Period
- 2
- Block
- s
- Category
- Alkali metal
- Electron configuration
- [He] 2s1
- Full configuration
- 1s2 2s1
- Electrons per shell
- 2, 1 (K L)
- Valence electrons
- 1
- Electronegativity (Pauling)
- 0.98
- First ionisation energy
- 5.392 eV
- Atomic radius (van der Waals)
- 182 pm
- State at room temperature
- Solid
- Melting point
- 180 °C
- Boiling point
- 1342 °C
- Density
- 0.534 g/cm³
- Common oxidation states
- +1
- Discovered
- 1817
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 1
Orbital diagram (outer electrons)
About lithium
Lithium is a chemical element with the symbol Li and atomic number 3. It is an alkali metal in group 1, period 2, s-block. The element was discovered in 1817. Lithium is a solid at room temperature, melting at 180 °C and boiling at 1342 °C. Its density of 0.534 g/cm³ is lower than water, so the metal floats.
Lithium electron configuration
The electron configuration of lithium is 1s2 2s1, or in short [He] 2s1. Its electrons occupy 2 shells: K = 2, L = 1. Lithium has 1 valence electron in the L shell (2s1), which is why it sits in group 1. When it forms cations, electrons leave the outermost subshell first: Li+ = [He] (like helium).
Filling order: 1s2(2) → 2s1(3)
Uses of lithium
The main uses of lithium include lithium-ion batteries for phones and electric vehicles, lubricating greases, heat-resistant glass and ceramics, and mood-stabilising medicine (lithium carbonate). For research and analysis you can browse lithium compounds in the AMI Scientific catalogue.
Safety
Lithium metal reacts with water and moisture, so it is stored under mineral oil or argon. Always read the safety data sheet (SDS) before working with a chemical.
Other elements in group 1
Frequently asked questions
What is the electron configuration of lithium?
The electron configuration of lithium (Li, atomic number 3) is 1s2 2s1, or [He] 2s1 in short. By shell: 2, 1.
How many valence electrons does lithium have?
Lithium has 1 valence electron.
Which group and period is lithium in?
Lithium is in group 1, period 2, s-block.
What is the atomic mass of lithium?
The relative atomic mass of lithium is 6.94. Use it to calculate molar mass with the molar mass calculator.
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