Scandium is a soft, silvery, yellow-white metal that belongs to Periodic Group 3 and is the leader of a group of ten metals known as the First Row Transition Elements. Scandium ranks 35th in terms of abundance in the Earth's crust. It tarnishes in the air and burns easily once ignited. It reacts with water to produce hydrogen gas and dissolves in a variety of acids.
Scandium is a very light metal with a relatively high melting point and good corrosion resistance. It is also a rare metal, not because it is difficult to find, but because it is difficult to find in a high concentration (i.e. an ore) and is thinly distributed around the world (0.0025% of the Earth's crust), making collection and purification costly and time-consuming.
