Dysprosium << dihs PROH see uhm >> (chemical symbol, Dy), is one of the lanthanide metals. Its atomic number (number of protons in its nucleus) is 66. Its relative atomic mass is 162.50. An element’s relative atomic mass equals its mass (amount of matter) divided by 1/12 of the mass of carbon 12, the most abundant form of carbon. The density of dysprosium is 8.559 grams per cubic centimeter at 25 °C (see Density). It has a melting point of 1412 °C and a boiling point of 2567 °C. For information on the position of dysprosium on the periodic table, see the article Periodic table.
The name of this element comes from the Greek word dysprositos, meaning hard to get. The French scientist Paul Emile Lecoq de Boisbaudran discovered dysprosium in 1886. It is found associated with erbium, holmium, and other lanthanides in the minerals gadolinite, euxenite, xenotime, and others. When cooled to low temperatures, it is strongly attracted by a magnet.
See also Rare earth.
