Gadolinium (symbol Gd, atomic number 64) is a rare-earth metal used as an MRI contrast agent and in neutron shielding. It is classified as a lanthanide and sits in the lanthanide series (f-block), period 6 of the periodic table.
Overview
Gadolinium is the chemical element with atomic number 64 and the symbol Gd. With a standard atomic weight of 157.25, 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. Gadolinium is a rare-earth metal used as an MRI contrast agent and in neutron shielding.
Atomic structure
An atom of Gadolinium has 64 protons in its nucleus and, when neutral, 64 electrons arranged in the configuration [Xe] 4f7 5d1 6s2. Its standard atomic weight of 157.25 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Gadolinium was discovered in 1880 by Jean Charles Galissard de Marignac. It follows Europium (Eu) and precedes Terbium (Tb) in order of atomic number.
| Atomic number | 64 |
|---|---|
| Symbol | Gd |
| Atomic mass | 157.25 |
| Category | Lanthanide |
| Group | — |
| Period | 6 |
| Electron configuration | [Xe] 4f7 5d1 6s2 |
| Phase at STP | Solid |
| Discovered | 1880 (Jean Charles Galissard de Marignac) |