Scandium is a transition metal having atomic number 21.
Electronic Configuration is .
It is a d block element having one electron in its d orbital and two electrons in the s orbital. So it loses its outer three electrons due to this its oxidation state is.
On releasing two electrons from s orbital Scandium forms an oxidation state. But it is very difficult to form a chemical species.
Sometimes Scandium forms an oxidation state but it needs very high energy.