21
Sc
Scandium
44.955907074566
Scandium (Sc)
Transition MetalGroup 3Period 4d-block-block
Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanoids. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia.
Latin name: Scandium
Atomic Number
21
Atomic Mass
44.955907074566 g/mol
Phase (STP)
Solid
Electron Config.
[Ar] 3d¹ 4s²
General
SymbolSc
Atomic Number21
Atomic Mass44.955907074566 g/mol
CategoryTransition Metal
Group3
Period4
Blockd-block
Electron Configuration[Ar] 3d¹ 4s²
Valence Electrons3
ColourSilver-white
Appearancesilvery white
CAS NumberCAS7440-20-2
Physical Properties
Phase (STP)Solid
Density2.985 g/cm³
Melting Point1540.85°C · 2805.53°F · 1814.00 K
Boiling Point2835.85°C · 5136.53°F · 3109.00 K
Atomic Properties
Atomic Radius184 pm
Covalent Radius159 pm
Van der Waals Radius211 pm
Electronegativity1.36 Pauling
Ionization Energy633 kJ/mol
Electron Affinity18 kJ/mol
Oxidation States+3
Ion ChargeSc³⁺
Thermodynamic
Molar Heat25.52 J/(mol·K)
Electromagnetic
Electrical TypeConductor
Electrical Conductivity1779359.43060498 S/m
Resistivity5.62e-7 Ω·m
Superconducting Point0.05 K
Volume Magnetic Susceptibility0.0002627
Mass Magnetic Susceptibility8.8e-9
Molar Magnetic Susceptibility3.956e-9
Crystal Structure
Crystal StructureHexagonal close-packed
Lattice Constant a3.309 pm
Lattice Constant c5.268 pm
Abundance
In Universe0.0003%
In Sun0.0004%
In Earth's Crust0.2200%
In Oceans0.00000015%
In Humans0.000028536407%
In Meteorites0.0640%
Discovery & History
Discovery Year1879
Discovered ByLars Fredrik Nilson
Country of DiscoverySweden
Isotopes of Scandium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Sc-45 | 100% | Stable | — |