Hafnium

Hafnium is the 72nd element in the periodic table, with an atomic mass of 178.49 amu, a density of 13.31 g/cm cubed, and electron levels of 2-8-18-32-10-2. Hafnium has a +4 valence, and is a member of group 4B, the element directly following the lanthanide series. Hf was discovered in 1923 by D. Coster of the Netherlands, and G. von Hevesy of Hungary. Hf melts at 2230.85 degrees C, and boils at 4601.85 degrees C. It was named after the city in which it was discovered, Copenhagen. (also known as Hafnia) It was first identified in zircon, which contains about 1% to 5% hafnium. Hf is ductile with a brilliant silver luster, and its properties are influenced by the amount of zirconium present, zirconium and hafnium being 2 of the most difficult elements to separate. Their chemistry is almost identical, yet hafnium is about twice as dense as zirconium. When heated to 700 degrees C, Hf rapidly absorbs hydrogen. Halogens can also react to hafnium to form tetrahalides. Hf is corrosion resistant, and is sometimes used in lamps.

June 18, 1997

Back to my chem page.

Back to my page.