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[haf-nee-uh m, hahf-] /ˈhæf ni əm, ˈhɑf-/
noun, Chemistry.
a gray, toxic metallic element with a high melting point (over 2000°C), found in most zirconium minerals. Symbol: Hf; atomic weight: 178.49; atomic number: 72; specific gravity: 12.1.
Origin of hafnium
1923; < New Latin Hafn(ia) Copenhagen + -ium Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for hafnium


a bright metallic element found in zirconium ores: used in tungsten filaments and as a neutron absorber in nuclear reactors. Symbol: Hf; atomic no: 72; atomic wt: 178.49; valency: 4; relative density: 13.31; melting pt: 2231±20°C; boiling pt: 4603°C
Word Origin
C20: New Latin, named after Hafnia, Latin name of Copenhagen + -ium
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for hafnium

rare element, 1923, Modern Latin, from Hafnia, Medieval Latin form of Danish Havn "harbor," the usual pre-1400 name of Copenhagen, Denmark, where it was discovered by physicist Dirk Coster (1889-1950) and chemist George de Hevesy (1885-1966).

Online Etymology Dictionary, © 2010 Douglas Harper
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hafnium in Medicine

hafnium haf·ni·um (hāf'nē-əm)
Symbol Hf
A metallic element found with zirconium and used in nuclear reactor control rods and in tungsten alloys used in filaments. Atomic number 72; atomic weight 178.49; melting point 2,230°C; boiling point 4,600°C; specific gravity 13.3; valence 4.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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hafnium in Science
Symbol Hf
A bright, silvery metallic element that occurs in zirconium ores. Because hafnium absorbs neutrons better than any other metal and is resistant to corrosion, it is used to control nuclear reactions. Atomic number 72; atomic weight 178.49; melting point 2,220°C; boiling point 5,400°C; specific gravity 13.3; valence 4. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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