Final answer:
Scandium is the lightweight metal named after Scandinavia, identified in the minerals euxenite and gadolinite by Lars Fredrik Nilson in 1879 and used in various applications.
Step-by-step explanation:
The lightweight metal in question, named after Scandinavia where it was first discovered, is Scandium. This metal was discovered in 1879 by Lars Fredrik Nilson in Uppsala, Sweden. Scandium is a rare, silvery-white metallic element that was identified spectroscopically in the minerals euxenite and gadolinite. Occurring in only trace amounts in many minerals, scandium is classified as a rare earth element and is used in various applications ranging from aerospace components to sporting goods. The discovery of scandium is a testament to the richness of Scandinavian mineral resources and their historical contributions to the field of chemistry and metallurgy. Despite its name suggesting a Scandinavian origin, the actual amount of scandium present in the Scandinavian peninsula is not particularly high.