Quick answerLithium (Li) is an alkali metal with atomic number 3 and an atomic mass of 6.94 (2023), in group 1, period 2. It was discovered by Johan August Arfwedson in 1817. It is used for rechargeable lithium-ion batteries and psychiatric medication. Its electron configuration is [He] 2s1.
Lithium is the lightest metal, so light it floats on water, and it powers the modern world through the rechargeable batteries in phones, laptops, and electric cars. It also steadies moods as a psychiatric medicine and strengthens the glass in phone screens. Demand for it has soared with the shift to electric vehicles.
Key facts
| Symbol | Li |
|---|---|
| Atomic number | 3 |
| Atomic mass | 6.94 (IUPAC standard atomic weight, 2023) |
| Category | alkali metal |
| Group | 1 |
| Period | 2 |
| Block | s-block |
| Electron configuration | [He] 2s1 |
| Discovered | Johan August Arfwedson, 1817 |
| Uses | rechargeable lithium-ion batteries, psychiatric medication, strengthened glass, aluminium smelting, aircraft alloys |
Overview
Lithium is the lightest of all metals and the least dense solid element, a soft, silvery metal that floats on water and reacts eagerly with it. It has atomic number 3, an atomic mass of 6.94, and the electron configuration [He] 2s1, with a single electron in its outer shell that it gives up easily. That is why it sits in group 1 with the other alkali metals. Johan August Arfwedson discovered it in 1817 in a mineral from a Swedish mine, and named it from the Greek word for stone, because it was found in rock rather than in plant ash like the other alkali metals known then. Lithium's defining modern role is energy storage. Rechargeable lithium-ion batteries power phones, laptops and electric cars, and they store electricity for power grids, because lithium is light and its ions move readily between electrodes. Demand has soared as transport and power go electric. Beyond batteries, lithium compounds steady moods as a psychiatric medicine used to treat bipolar disorder, and they strengthen the glass in phone screens, help smelt aluminium, and form light, strong alloys for aircraft. Lithium is found in salty brines beneath deserts in South America and in hard-rock mines, mainly in Australia, and extracting it uses large amounts of water and energy.
Frequently asked questions
What is lithium used for?
Lithium is mainly used in rechargeable lithium-ion batteries for phones, laptops, electric cars and grid storage. It is also used as a psychiatric medicine for bipolar disorder, to strengthen glass in phone screens, to help smelt aluminium, and in light aircraft alloys. Demand has soared as transport and power go electric.
What is the symbol for lithium?
The chemical symbol for lithium is Li, from its name, which comes from the Greek word lithos, meaning stone. Johan August Arfwedson discovered it in 1817 in a mineral from a Swedish mine, and named it for stone because it was found in rock. Lithium has atomic number 3 and an atomic mass of 6.94.
What is the atomic number of lithium?
Lithium has atomic number 3, so it is the third element in the periodic table. Its atom holds three protons and three electrons, and its standard atomic mass is 6.94. It is an alkali metal in group 1 and period 2, with the electron configuration [He] 2s1, a single electron in its outer shell.
Is lithium a metal?
Yes, lithium is a metal, and it is the lightest metal of all. It is a soft, silvery alkali metal in group 1 of the periodic table, so light that it floats on water, though it reacts with the water. It is the least dense solid element, and it is stored under oil because it tarnishes quickly in air.
Where is lithium found?
Lithium is found in salty brines beneath desert salt flats, mainly in South America, and in hard-rock mines, mainly in Australia. It is also present in small amounts in seawater and in some minerals. Brine is pumped to the surface and left to evaporate in shallow ponds before the lithium is refined for batteries.
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Sodium (Na) — another alkali metal, atomic number 11
- Potassium (K) — another alkali metal, atomic number 19
- Rubidium (Rb) — another alkali metal, atomic number 37
- Caesium (Cs) — another alkali metal, atomic number 55
- Francium (Fr) — another alkali metal, atomic number 87
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.