Praseodymium
Praseodymium. Vial containing samples of the rare earth metal Praseodymium (Pr). The rare earth metals, or rare earth elements, are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium. Praseodymium is a soft silvery metallic element. It is used in carbon arc lights and to colour glass and enamels yellow.