Lanthanides

The lanthanides are a series of 14 metallic elements that appear at the bottom of the periodic table. Lanthanum, the element preceding the lanthanides in the periodic table, is usually also included in a discussion of the lanthanides since all 15 elements have very similar properties. When first discovered and isolated, the lanthanides were called the rare earth elements. Many uses have been found for these elements and their compounds despite their expense.