Atomic number: 21

Symbol: Sc

Category: transition metal

Density at 25°C: solid 2.985 g·cm−3

Scandium is a rare earth metal. It was so tricky to refine from ores that it didn't make much of an appearance until the 1970s, and then mostly for alloys.

Occasionally it is used with other elements as part of medical lasers.

99.9998% scandium from sublimation process. image adapted from wikipedia

Use, natural applications or common combinations: 

  • Alloys
  • Lasers

Basic characteristics:

  • Standard atomic weight: 44.955 912(6)
  • Melting point: 1541 °C
  • Boiling point: 2836 °C
  • Radioactivity:  naturally stable