Sc
Scandium
Element 21 · Transition metal
Scandium (Sc)
Scandium is a light, silvery transition metal. It is rare and expensive, but small amounts dramatically strengthen aluminium.
- Transition metal
- Period 4
- Group 3
- d-block
- solid at room temperature
Key properties
- Atomic mass
- 44.9559
- u
- Electron configuration
- [Ar] 3d1 4s2
- Melting point
- 1,540.9 °C
- 1,814 K
- Boiling point
- 2,835.9 °C
- 3,109 K
- Density
- 2.99 g/cm³
- Electronegativity
- 1.36
- Pauling
- Atomic radius
- 211 pm
- van der Waals
- 1st ionisation energy
- 6.561 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about scandium
- 01
Mendeleev predicted its properties in 1871 as “eka-boron”.
- 02
Aluminium–scandium alloys are used in fighter jets and high-end bicycle frames.
- 03
Scandium iodide in stadium lights produces a light close to natural sunlight.
Applications
What is scandium used for?
- Aerospace aluminium alloys
- Sports equipment
- Metal-halide lamps
- Solid oxide fuel cells
History
Discovery & name origin
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 21
- Atomic mass
- 44.9559 u
- Group
- 3
- Period
- 4
- Block
- d-block
- Electron configuration
- [Ar] 3d1 4s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d1
- Electrons per shell
- 2, 8, 9, 2
- Electronegativity (Pauling)
- 1.36
- Electron affinity
- 0.188 eV
- Atomic radius (van der Waals)
- 211 pm
- Stable isotopes
- 1
Oxidation states
Highlighted: common oxidation states (+3).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st633.1
- 2nd1,235
- 3rd2,388.6
- 4th7,090.6
- 5th8,843
- 6th10,679
- 7th13,310
- 8th15,250
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 1,814 K · 1,540.9 °C · 2,805.5 °F
- Boiling point
- 3,109 K · 2,835.9 °C · 5,136.5 °F
- Density
- 2.99 g/cm³
- Molar heat capacity
- 25.52 J/(mol·K)
- Appearance
- Silvery white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Scandium questions
What is Sc on the periodic table?
Sc is the symbol for scandium, element 21 on the periodic table. It sits in group 3, period 4, in the transition metal category, and has an atomic mass of 44.9559.
What is the atomic number of scandium?
Scandium has atomic number 21, so every scandium atom has 21 protons in its nucleus. Its symbol is Sc and its atomic mass is 44.9559.
Who discovered scandium?
Scandium was discovered by Lars Fredrik Nilson in 1879 (Sweden). The name comes from Latin Scandia, “Scandinavia”.
What is scandium used for?
Scandium is used for: aerospace aluminium alloys; sports equipment; metal-halide lamps; solid oxide fuel cells.
Is scandium a metal?
Yes. Scandium is a transition metal, one of the metallic elements.
What is the electron configuration of scandium?
The electron configuration of scandium is [Ar] 3d1 4s2. Its 21 electrons are arranged in shells as 2, 8, 9, 2.