an excellent, silvery, metallic element divided from ores of zirconium and utilized in nuclear reactor control rods, as a getter for air and nitrogen, plus the make of tungsten filaments. Atomic quantity 72; atomic body weight 178.49; melting point 2,220°C; boiling-point 5,400°C; specific gravity 13.3; valence 4. See dining table at factor.
A metallic chemical element (expression Hf) with an atomic quantity of 72.
A metallic section of atomic number 72 present as well as zirconium into degree of just oneper cent to 5percent in zirconium nutrients. It's a poisonous, ductile material with a fantastic gold luster, has actually an atomic fat of 178.49, and has a top melting point (2227° C). It's found in atomic reactors, and incandescent lights as a scavenger of air and nitrogen. See in addition norium.
a grey tetravalent metallic factor that resembles zirconium chemically and is present zirconium nutrients; utilized in filaments for its ready emission of electrons