Lanthanum - Definition
lanthanum
n 1: a white soft metallic element that tarnishes readily;
occurs in rare earth minerals and is usually classified as
a rare earth [syn: lanthanum, La, atomic number 57]
n 1: a white soft metallic element that tarnishes readily;
occurs in rare earth minerals and is usually classified as
a rare earth [syn: lanthanum, La, atomic number 57]