lanthanide (rare earth metal)

Introduction

The elements lanthanum (57) through lutetium (71).

From the Greek lantheneis meaning to lie hidden.

Occurrence

• despite the name, lanthanides are NOT rare
• lanthanum (La), cerium (Ce) & neodymium (Nd) are more common than lead (Pb)

Characteristics

• silvery-white, but tarnish in air
• all lanthanides are very reactive & electropositive
• predominantly cationic
  • +3 oxidation state most important chemically
• low charge density despite +3 charge because of large size

Uses

• alloys
• lenses
• magnets

More general terms

• chemical element
• metal

More specific terms

• cerium [Ce]
• dysprosium [Dy]
• erbium [Er]
• europium [Eu]
• gadolinium [Gd]
• holmium [Ho]
• lanthanum [La]
• lutetium [Lu] (lutecium)
• neodymium [Nd]
• praseodymium [Pr]
• promethium [Pm]
• samarium [Sm]
• terbium [Tb]
• thulium [Tm]
• ytterbium [Yb]