Scandium (Sc): Electron Configuration, Properties and Uses
Scandium (Sc): Electron Configuration, Properties and Uses
Electron configuration [Ar] 4s2 3d1 · group 3 · period 4 · Ar 44.956
Scandium data
- Atomic number
- 21
- Relative atomic mass
- 44.956
- Group
- 3
- Period
- 4
- Block
- d
- Category
- Transition metal
- Electron configuration
- [Ar] 4s2 3d1
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d1
- Electrons per shell
- 2, 8, 9, 2 (K L M N)
- Valence electrons
- 3
- Electronegativity (Pauling)
- 1.36
- First ionisation energy
- 6.561 eV
- Atomic radius (van der Waals)
- 211 pm
- State at room temperature
- Solid
- Melting point
- 1541 °C
- Boiling point
- 2836 °C
- Density
- 2.99 g/cm³
- Common oxidation states
- +3
- Discovered
- 1879
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 9 · N 2
Orbital diagram (outer electrons)
About scandium
Scandium is a chemical element with the symbol Sc and atomic number 21. It is a transition metal in group 3, period 4, d-block. The element was discovered in 1879. Scandium is a solid at room temperature, melting at 1541 °C and boiling at 2836 °C.
Scandium electron configuration
The electron configuration of scandium is 1s2 2s2 2p6 3s2 3p6 4s2 3d1, or in short [Ar] 4s2 3d1. Its electrons occupy 4 shells: K = 2, L = 8, M = 9, N = 2. For transition metals, valence electrons are counted from the 4s and 3d subshells: 2 + 1 = 3, matching group 3. When it forms cations, electrons leave the outermost subshell first: Sc3+ = [Ar] (like argon).
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s2(12) → 3p6(18) → 4s2(20) → 3d1(21)
Uses of scandium
The main uses of scandium include aluminium-scandium alloys for bicycle frames and aircraft parts, and metal-halide lamps.
Safety
As a solid metal, scandium is not especially hazardous. Fine powder can burn, and its compounds should be handled according to their SDS. Always read the safety data sheet (SDS) before working with a chemical.
Other elements in group 3
Frequently asked questions
What is the electron configuration of scandium?
The electron configuration of scandium (Sc, atomic number 21) is 1s2 2s2 2p6 3s2 3p6 4s2 3d1, or [Ar] 4s2 3d1 in short. By shell: 2, 8, 9, 2.
How many valence electrons does scandium have?
Scandium has 3 valence electrons.
Which group and period is scandium in?
Scandium is in group 3, period 4, d-block.
What is the atomic mass of scandium?
The relative atomic mass of scandium is 44.956. Use it to calculate molar mass with the molar mass calculator.
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