cesium
or cae·si·um
[see-zee-uh m]
- a rare, highly reactive, soft, metallic element of the alkali metal group, used chiefly in photoelectric cells. Symbol: Cs; atomic weight: 132.905; atomic number: 55; specific gravity: 1.9 at 20°C; melts at 28.5°C.
Show More
Origin of cesium
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for cesium
Contemporary Examples
Even at the Chernobyl meltdown in 1986, he pointed out, cesium and iodine were the problem.
cesium
- the usual US spelling of caesium
Show More
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
Word Origin and History for cesium
n.
also caesium, rare alkaline metal, 1861, coined by Bunsen and Kirchhoff in 1860 in Modern Latin (caesium), from Latin caesius "blue-gray" (especially of eyes), in reference to the two prominent blue lines in its spectrum, by which it was first identified.
Show More
Online Etymology Dictionary, © 2010 Douglas Harper
cesium
- A soft ductile metal, liquid at room temperature, the most electropositive and alkaline of the elements, used in photoelectric cells. Atomic number 55.
Show More
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
cesium
[sē′zē-əm]
- A soft, ductile, silvery-white element of the alkali group. It is liquid at room temperature and is the most reactive of all metals. Cesium is used to make photoelectric cells, electron tubes, and atomic clocks. Atomic number 55; atomic weight 132.905; melting point 28.5°C; boiling point 690°C; specific gravity 1.87; valence 1. See Periodic Table.
Show More
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.