单词 | francium |
释义 | francium[ fran-see-uhm ] / ˈfræn si əm / noun Chemistry.a radioactive element of the alkali metal group. Symbol: Fr; atomic number: 87. Origin of francium1945–50; after France where first identified; see -ium Words nearby franciumFrancis of Assisi, Francis of Paula, Francis of Sales, Francis turbine, Francis Xavier, francium, francize, Franck, Franco, Franco-American, Franco-Belgian system Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Example sentences from the Web for francium
British Dictionary definitions for franciumfrancium / (ˈfrænsɪəm) / nounan unstable radioactive element of the alkali-metal group, occurring in minute amounts in uranium ores. Symbol: Fr; atomic no: 87; half-life of most stable isotope, 223 Fr: 22 minutes; valency: 1; melting pt: 27°C; boiling pt: 677°C Word Origin for franciumC20: from New Latin, from France + -ium; so-called because first found in France 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 Medical definitions for franciumfrancium [ frăn′sē-əm ] n. Symbol FrAn extremely unstable radioactive element of the alkali metals, having approximately 19 isotopes, the most stable of which is Fr 223 with a half-life of 21 minutes. Atomic number 87. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. Scientific definitions for franciumfrancium [ frăn′sē-əm ] FrAn extremely unstable, radioactive element of the alkali group. It is the heaviest metal of the group. Francium occurs in nature, but less than 28.35 g (1 oz) is present in the Earth's crust at any time. It has approximately 19 isotopes, the most stable of which is Fr 223 with a half-life of 21 minutes. Atomic number 87; valence 1. See Periodic Table. The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. |
随便看 |
|
英语词典包含192737条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。