Element 3
Lithium (Li)
Lithium (Li) is element 3 of the periodic table, an alkali metal in period 2, group 1 (s-block) with an atomic mass of 6.94 and is a solid at standard conditions.
At a glance
- Atomic number
- 3
- Symbol
- Li
- Atomic mass
- 6.94 u
- Category
- Alkali metals
- Period
- 2
- Group
- 1
- Block
- s-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s1
- Shorthand configuration
- [He] 2s1
- Electrons per shell
- 2, 1
- Oxidation states
- +1
Physical properties
- Melting point
- 453.69 K (180.54 °C)
- Boiling point
- 1,615 K (1,341.85 °C)
- Density
- 0.534 g/cm³
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 0.98
- Atomic radius
- 167 pm
- Covalent radius
- 128 pm
- Van der Waals radius
- 182 pm
- First ionization energy
- 520 kJ/mol
- Electron affinity
- 60 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Li-7 | 7.016 | 92.41% | Stable |
Common uses
- Batteries
- Mood stabilizers
- Ceramics
- Lubricants
Discovery
- Year
- 1817
- Discovered by
- Johan August Arfwedson
- Country
- Sweden
Frequently asked questions
- Is lithium a metal?
- Yes. Lithium is a metal, classified as an alkali metal on the periodic table.
- How many protons does lithium have?
- Lithium has 3 protons. Its atomic number is 3, which is also the number of electrons in a neutral atom of lithium.
- What group and period is lithium in?
- Lithium is in group 1 and period 2 of the periodic table, in the s-block.
- What is the atomic mass of lithium?
- The atomic mass of lithium is 6.94 u (unified atomic mass units).
Keep exploring
Lithium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.