Scandium (Sc) is a soft metallic element with atomic number 21. The reason it's called scandium is that it was first discovered in Scandinavia in the 19^th century. The only naturally occurring scandium isotope is ⁴⁵Sc (21 protons, 24 neutrons).

Scandium can be combined together with aluminium to form alloys which are stronger than pure aluminium but still very lightweight. Such alloys are used in various industries, such as aviation, firearms and sporting equipment.