Ta Tantalum 73 180.94788 5 6 d 73 2996.0 5425.0 [Xe] 4f14 5d3 6s2 2 8 18 32 11 2 16.6 0.00017% Gray Cubic: Body centered 1.5 1.34 {"1":"761","2":"1500"} 761 31 5 1.49 10.9 36.0 737.0 0.14 57.5 0 Solid, Conductor, TransitionMetal, Metal, Stable, Natural TAN-te-lem Rare, gray, heavy, hard but ductile, metal with a high melting point. Often used as an economical substitute for platinum. Tantalum pentoxide is used in capacitors and in camera lenses to increase refracting power. It and its alloys are corrosion and wear resistant so it is used to make surgical and dental tools. Chiefly occurs in the mineral tantalite. Always found with niobium. 51xFP1Yn3g0 Tantalum

Praseodymium was first identified in 1885, in Vienna, by the Austrian chemist Carl Auer von Welsbach.

It was discovered in didymium, a substance incorrectly said by Carl Gustav Mosander to be a new element in 1841.

Pure metallic praseodymium was first produced in 1931. From the Greek word prasios, green, and didymos, twin 73 1802 Anders Ekeberg Sweden From the Greek word "Tantalos" meaning "father of Niobe"

Praseodymium is considered to be moderately toxic

Praseodymium is usually stored under a light mineral oil or sealed in glass

Praseodymium is used as an alloying agent with magnesium to create high-strength metals that are used in aircraft engines.

Misch metal, used in making cigarette lighters, contains about 5% praseodymium metal.

Praseodymium is used to make specialized yellow glass goggles for glass blowers and welders.