Terbium (symbol Tb, atomic number 65) is a rare-earth metal used in green phosphors and magnetostrictive alloys. It is classified as a lanthanide and sits in the lanthanide series (f-block), period 6 of the periodic table.
Overview
Terbium is the chemical element with atomic number 65 and the symbol Tb. With a standard atomic weight of 158.93, it is a lanthanide. In the periodic table it occupies the lanthanide series (f-block) and period 6, and under standard conditions it is normally a solid. Terbium is a rare-earth metal used in green phosphors and magnetostrictive alloys.
Atomic structure
An atom of Terbium has 65 protons in its nucleus and, when neutral, 65 electrons arranged in the configuration [Xe] 4f9 6s2. Its standard atomic weight of 158.93 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Terbium was discovered in 1843 by Carl Gustaf Mosander. It follows Gadolinium (Gd) and precedes Dysprosium (Dy) in order of atomic number.
| Atomic number | 65 |
|---|---|
| Symbol | Tb |
| Atomic mass | 158.93 |
| Category | Lanthanide |
| Group | — |
| Period | 6 |
| Electron configuration | [Xe] 4f9 6s2 |
| Phase at STP | Solid |
| Discovered | 1843 (Carl Gustaf Mosander) |