Scandium (symbol Sc, atomic number 21) is a light transition metal used in high-performance aluminium-scandium alloys. It is classified as a transition metal and sits in group 3, period 4 of the periodic table.
Overview
Scandium is the chemical element with atomic number 21 and the symbol Sc. With a standard atomic weight of 44.956, it is a transition metal. In the periodic table it occupies group 3 and period 4, and under standard conditions it is normally a solid. Scandium is a light transition metal used in high-performance aluminium-scandium alloys.
Atomic structure
An atom of Scandium has 21 protons in its nucleus and, when neutral, 21 electrons arranged in the configuration [Ar] 3d1 4s2. Its standard atomic weight of 44.956 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Scandium was discovered in 1879 by Lars Fredrik Nilson. It follows Calcium (Ca) and precedes Titanium (Ti) in order of atomic number.
| Atomic number | 21 |
|---|---|
| Symbol | Sc |
| Atomic mass | 44.956 |
| Category | Transition metal |
| Group | 3 |
| Period | 4 |
| Electron configuration | [Ar] 3d1 4s2 |
| Phase at STP | Solid |
| Discovered | 1879 (Lars Fredrik Nilson) |