ElementsWhat is scandium?
Scandium is a soft, silvery metal. It is spread thinly through many rocks and is costly to collect, so very little is produced each year.
What is scandium used for?
Strong, light aluminium alloys for aircraft and sports goods such as bicycle frames, and bright stadium lamps.
Where the name comes from
From Scandia, the Latin name for Scandinavia, where its mineral was found.
Key facts
- Symbol
- Sc
- Atomic number
- 21
- Atomic mass
- 44.95591 u
- Family
- Transition metal
- Period
- 4
- Group
- 3
- Block
- d
- State at room temperature
- Solid
- Melting point
- 1,541 °C (1,814 K, 2,806 °F)
- Boiling point
- 2,836 °C (3,109 K, 5,137 °F)
- Density
- 2.99 g/cm³
- Electrons per shell
- 2, 8, 9, 2
- Electron configuration
- [Ar]4s2 3d1
- Common oxidation states
- +3
- Electronegativity (Pauling)
- 1.36
- First ionisation energy
- 6.561 eV
- Electron affinity
- 0.188 eV
- Atomic radius (van der Waals)
- 211 pm
- Discovered
- 1879
Place in the periodic table
Scandium is element number 21. It sits in period 4 (row 4) of the periodic table, in group 3 (column 3), and belongs to the d-block. Just before it comes calcium (20), and just after it comes titanium (22). In the same column, yttrium is below it. Elements in one column tend to behave alike.
Family: Transition metals.
Physical properties
At room temperature scandium is a solid. It melts at 1,541 °C and boils at 2,836 °C, so it stays liquid over a range of 1,295 degrees. Its density is 2.99 grams per cubic centimetre, so a one-litre block would weigh about 2.99 kilograms. By density it ranks 70th among the 96 elements with a measured value.
Inside the atom
An atom of scandium has 21 protons in its nucleus and, when neutral, 21 electrons around it. The electrons are arranged in 4 shells: 2, 8, 9, 2. The outermost shell holds 2 electrons. Written in full, the electron configuration is [Ar]4s2 3d1.
Its electronegativity on the Pauling scale is 1.36. This number shows how strongly an atom pulls shared electrons towards itself: fluorine, the strongest, is 3.98. Removing one electron from an atom takes 6.561 electronvolts (about 633 kilojoules per mole). One mole of scandium weighs 44.95591 grams, so a single gram contains about 1.34 × 1022 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains scandium with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.