Scandium (Sc)
Scandium (Sc) is element 21, a transition metal. Atomic mass 44.955907, configuration [Ar] 3d¹ 4s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 21 |
|---|---|
| Symbol | Sc |
| Standard atomic weight | 44.955907(4) |
| Category | Transition Metal |
| Group | 3 |
| Period | 4 |
| State at room temperature | Solid |
| Electron configuration | [Ar] 3d¹ 4s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +3 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.36 |
| First ionization energy | 633 kJ/mol |
| Electron affinity | 18.14 kJ/mol |
| Atomic radius | 184 pm |
| Density | 2.99 g/cm³ |
| Melting point | 1541°C |
| Boiling point | 2836°C |
| Specific heat | 0.568 J/(g·°C) |
Natural isotopes
- Sc-45: Stable
Common uses
- Aerospace alloys (Aluminum-Scandium for MiG fighters)
- Stadium lighting
Where it matters
- Prediction validation (Mendeleev predicted it as 'Eka-boron')
Hazards
- Elemental dust is flammable
History
| Discovered | 1879 |
|---|---|
| Discovered by | Lars Fredrik Nilson |
| Name | From Latin Scandia (Scandinavia) |