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Transition metals

Scandium

A light transition metal used in high-performance alloys.

Atomic #21Mass44.956Blockd-blockPeriod4Group3
Sc21 · 44.956
3D Atom Explorer

Inside the Scandium atom

Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Scandium atom step by step.

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Electron configuration

[Ar] 3d1 4s2

A neutral Scandium atom has 21 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.

Shell distribution

Shell 12 e⁻Shell 28 e⁻Shell 39 e⁻Shell 42 e⁻

Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.

Properties

Physical & atomic properties

State (room temp)
Solid
Melting point
1814 K (1541 °C)
Boiling point
3109 K (2836 °C)
Density
2.989 g/cm³
Electronegativity
1.36 Pauling
Atomic radius
160 pm
1st ionization energy
633 kJ/mol
Category
Transition metals
History

Discovery & naming

Discovered
1879
Discovered by
Lars Fredrik Nilson
Origin of name
Latin 'Scandia', for Scandinavia.

Notable uses

Lightweight high-performance alloys and stadium lighting.

Cosmic origin

Where Scandium comes from

Supernovae

A rare, awkward element that current models underproduce. Explosive burning appears to be the main source.

Simplified origin map — many elements form through more than one astrophysical pathway.

Summary

Atomic number
21
Atomic mass
44.956
Category
Transition metals
Group · Period
3 · 4
Block
d-block
Shells
2 · 8 · 9 · 2