Scandium (Sc)

Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been classified as a rare-earth element.

Atomic Number

21

Atomic Mass

44.956 u

Category

transition metal

Phase

solid

Density

2.99 g/cm³

Electron Shells

2, 8, 9, 2

Atomic Structure

Protons: 21 • Electrons: 21 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹

Discovery

1879 • Lars Fredrik Nilson