59

Pr

Praseodymium
140.90765 (2)
 Historical Information

In 1885, Carl Auer von Welsbach separated an "earth" called didymia obtained from the mineral samarskite into two earths, praseodymia and neodymia, which gave salts of different colours. The separation required the repeated fractionation of ammonium didymium nitrate.

Basic Information Shells
  • Name:Praseodymium
  • Symbol: Pr
  • Atomic number: 59
  • Atomic weight:140.90765 (2)
  • Standard state: solid at 298 K
  • Group in periodic table:
  • Group name:Lanthanoid
  • Period in periodic table: 6
  • Block in periodic table: f-block
  • Classification: Metallic
 Praseodymium
Uses Trivia
  • Misch metal, used in making cigarette lighters, contains about 5 praseodymium metal

It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that "spalls" away when exposed to air.