Scandium was discovered by Lars Fredrik Nilson, a Swedish chemist, in 1879 in England. Nilson was able to prepare about 2 g of scandium oxide by processing 10 kg of euxenite and other residues of rare-earth minerals.
Atomic number: 21
Atomic weight: 44.956
Group, period, block: 3, 4, d
Color: silvery white
Classification: transition metal
Electron configuration: 3d1 4s2
Density: 2.985 g/cm-3
Melting point: 1814 K, 1541 °C, 2806 °F
Boiling point: 3109 K, 2836 °C, 5136 °F
Oxidation states: 3, 2, 1
Electronegativity: 1.36 (Pauling scale)
Ionization energies: 1st: 633.1 kJ·mol-1
Covalent radius: 170±7 pm
Van der Waals radius: 211 pm
There is only one naturally occurring isotope of potassium exists, 45Sc.