CAS Number7440-25-7
PubChem CID23956
Atomic Radius146
Atomic Volume10.9
Atomic Weight180.948
Boiling Point5,458
Bulk Modulus
CategoryTransition metals
Crystal StructureBody Centered Cubic
Covalent Radius170
Electrical Resistivity
Electron Configuration[Xe] 4f14 5d3 6s2
Electrons per shell2, 8, 18, 32, 11, 2
Heat of Fusion36
Heat of Vaporization735
Ionization Potential7.55
Magnetic Ordering
Magnetic Susceptibility
Mass Number73
Melting Point3,017
Atomic Number181
Oxidation States-1, 2, 3, 4, 5
Poisson Ratio
Shear Modulus
Specific Heat Capacity0.14
Thermal Conductivity0.575
Van der Waals radius
Young's Modulus
Abundance in Earth's crust0.00017%
Abundance in Universe8×10-9%
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"

Isotopes of Praseodymium

Standard Atomic Weight


Stable Isotopes

180Ta 181Ta

Unstable Isotopes

155Ta 156Ta 157Ta 158Ta 159Ta 160Ta 161Ta 162Ta 163Ta 164Ta 165Ta 166Ta 167Ta 168Ta 169Ta 170Ta 171Ta 172Ta 173Ta 174Ta 175Ta 176Ta 177Ta 178Ta 179Ta 182Ta 183Ta 184Ta 185Ta 186Ta 187Ta 188Ta 189Ta 190Ta

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.