Lithium (symbol Li, atomic number 3) is a soft alkali metal at the heart of rechargeable lithium-ion batteries and mood-stabilising medicine. It is classified as a alkali metal and sits in group 1, period 2 of the periodic table.
Overview
Lithium is the chemical element with atomic number 3 and the symbol Li. With a standard atomic weight of 6.94, it is a alkali metal. In the periodic table it occupies group 1 and period 2, and under standard conditions it is normally a solid. Lithium is a soft alkali metal at the heart of rechargeable lithium-ion batteries and mood-stabilising medicine.
Atomic structure
An atom of Lithium has 3 protons in its nucleus and, when neutral, 3 electrons arranged in the configuration [He] 2s1. Its standard atomic weight of 6.94 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Lithium was discovered in 1817 by Johan August Arfwedson. It follows Helium (He) and precedes Beryllium (Be) in order of atomic number.
| Atomic number | 3 |
|---|---|
| Symbol | Li |
| Atomic mass | 6.94 |
| Category | Alkali metal |
| Group | 1 |
| Period | 2 |
| Electron configuration | [He] 2s1 |
| Phase at STP | Solid |
| Discovered | 1817 (Johan August Arfwedson) |