Scandium (Sc)
Transition metal
Scandium is a light, silvery transition metal that is scattered so thinly through the Earth's crust that it took a century to collect enough to study properly. Small additions of it dramatically strengthen aluminium.
Position on the periodic table
Atomic properties
| Atomic number | 21 |
|---|---|
| Atomic mass | 44.9559 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d1 |
| Noble gas shorthand | [Ar] 3d1 4s2 |
| Electrons per shell | 2, 8, 9, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | +3 |
| Electronegativity (Pauling) | 1.36 |
| Covalent radius (approx.) | 170 pm |
| First ionization energy | 633.1 kJ/mol |
| Electron affinity | 18 kJ/mol |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 2.985 g/cm³ |
| Melting point | 1540.8 °C (1814 K) |
| Boiling point | 2835.8 °C (3109 K) |
| Appearance | silvery white |
| Radioactive | No |
| Origin | Occurs naturally |
Electron configuration of scandium
Scandium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d1, usually shortened to [Ar] 3d1 4s2. Its electrons occupy 4 shells (2, 8, 9, 2), placing it in period 4 of the d-block. Explore it interactively in the electron configuration calculator.
Uses of scandium
- Aluminium-scandium alloys for aerospace and sports gear
- High-intensity stadium lights (scandium iodide lamps)
- Solid-oxide fuel cells
Biological role: None known.
Occurrence: Widely dispersed in trace amounts; rarely concentrated into mineable deposits.
Common compounds of scandium
Sc2O3
Scandium oxide
ScI3
Scandium iodide
History and discovery
Discovered: 1879 — Lars Fredrik Nilson. Name origin: From Scandia, the Latin name for Scandinavia, where its ore was found.
Lars Fredrik Nilson discovered scandium in 1879 in Scandinavian minerals, matching Mendeleev's prediction closely.
Safety notes
Low toxicity, but rarely encountered outside specialist labs and alloys.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Scandium
1. What is the chemical symbol of Scandium?
2. What is the atomic number of Scandium?
3. Which category does Scandium belong to?
4. What is the state of Scandium at room temperature?
5. Which period of the periodic table is Scandium in?
Scandium FAQs
What is the atomic number of scandium?
Scandium's atomic number is 21 — every scandium atom has 21 protons in its nucleus.
What is the symbol for scandium?
Sc. From Scandia, the Latin name for Scandinavia, where its ore was found.
Is scandium a metal, nonmetal, or metalloid?
Scandium is classified as a transition metal.
What state is scandium at room temperature?
At about 25 °C, scandium is a solid. It melts at 1540.8 °C.
What is scandium used for?
Key uses include: aluminium-scandium alloys for aerospace and sports gear; high-intensity stadium lights (scandium iodide lamps); solid-oxide fuel cells.
Related elements
Keep working with this element
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