Symbol

Dy

Atomic Number

66

Atomic Mass

162.50

Family

Lanthanide (Rare Earth Metal) Pronunciation

dis-PRO-zee-um

Overview

Dysprosium is one of 15 rare earth elements. The name rare earth is misleading because the elements in this group are not especially uncommon. However, they often occur together in the earth and are difficult to separate from each other. A better name for the rare earth elements is lanthanides. This name comes from the element lanthanum, which is sometimes considered part of the lanthanides group in the periodic table. The periodic table is a chart that shows how chemical elements are related to one another.

Dysprosium was discovered in 1886, but was not commercially available until after 1950. The reason for the long delay was that methods for separating dysprosium from other lanthanides had not been developed. Dysprosium has relatively few applications today.

Discovery and Naming

In 1787, Carl Axel Arrhenius (1757-1824), a Swedish army officer and...