Praseodymium was once included with neodymium and samarium as a single element known as didymium. In 1879 samarium was separated from didymium. In 1886, Welsbach, a German chemist, further resolved didymium into the two elements - praseodymium and neodymium. Praseodymium received its name from the Greek words: Prasios -- for green and didymos -- for twin. Neodymium in being separated at the same time was referred to as the Neo, or "new" twin.
Today, praseodymium is primarily obtained through solvent extraction processing of bastnaesite ((REE)(CO3)(F)) ores in China.
Praseodymium is a soft silvery lustrous metallic ductile element, which may be cut with a knife. It is reactive and develops a green oxide coating, which spalls off in air. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium. Dilute acids also attack it, and as such the metal is generally stored in an inert atmosphere or in mineral oil.
APPLICATIONS OF PRASEODYMIUM
Magnets: Praseodymium can be used as a substitute for neodymium in super magnets. PrNi5 alloy also demonstrates magnetocaloric characteristics.
Glass and Ceramics: Praseodymium is a doping agent in fibre optic cables where the cable is used as a signal amplifier. Praseodymium salts are used to give glass, enamels and cubic zirconia a yellow color. As a component of didymium, praesodymium is used to make certain types of welder's and glass blower's goggles and other UV protective glasses
Electronics: Praseodymium forms the core of carbon arc lights, which are used in the motion picture industry for studio lighting and projector lights. It is also used in CAT scan scintillators.
Materials: Praseodymium's primary use is as an alloying agent with magnesium to create high-strength metals used in aircraft engines. Praseodymium also makes up about 5% of Mischmetal, a material that is used to make flints for lighters. Pr2O3, like the other rare earth oxides, is among the most refractory substances known and is also used in automotive exhaust catalytic converters.
LINKS: For chemical and physical properties: www.webelements.com or http://education.jlab.org/itselemental/ele059.html