cesium

noun
ce·si·um | \ˈsē-zē-əm also -zhē- \

Definition of cesium 

: a silver-white soft ductile element of the alkali metal group that is the most electropositive element known and that is used especially in photoelectric cells — see Chemical Elements Table

Examples of cesium in a Sentence

Recent Examples on the Web

Gases unleashed by the damage exploded, sending plumes of radioactive particles like iodine, cesium, and plutonium into the atmosphere. Vince Beiser, WIRED, "The Robot Assault On Fukushima," 26 Apr. 2018 The particles grab on to ions of cesium, strontium, and other dangerous isotopes in the water, making room for them by spitting out sodium. Vince Beiser, WIRED, "Fukushima’s Other Big Problem: A Million Tons of Radioactive Water," 27 Apr. 2018 The Harvard chemist takes two individual atoms, a sodium and a cesium, each about 10,000 times smaller than a bacterium. Sophia Chen, WIRED, "Chemists Orchestrate the Molecular Union of Two Single Atoms," 27 Apr. 2018 Lasers are used to slow and cool the atoms to near absolute zero, and then more lasers are used to elevate the ball of cesium up the chamber. Jay Bennett, Popular Mechanics, "The Centuries-Long Quest to Measure One Second," 24 Mar. 2017 The calibration is done with the alkali metal cesium. Jay Bennett, Popular Mechanics, "The Centuries-Long Quest to Measure One Second," 24 Mar. 2017 The concentrations of radioactive cesium near Japan, for example, were much higher than the concentrations along the west coast of the US. Rachel Becker, The Verge, "Katsuko Saruhashi turned radioactive fallout into a scientific legacy," 22 Mar. 2018 A few months after that incident, in Tokyo, a protester was arrested for landing a drone carrying a harmless amount of radioactive cesium on the prime minister’s office. Michael Laris, Washington Post, "Drones keep entering no-fly zones over Washington, raising security concerns," 13 Jan. 2018 After preliminary measurements are completed, the physicists plan to install a low-temperature cesium iodide detector to search for dark matter. Pallava Bagla, Science | AAAS, "India joins hunt for dark matter," 31 Aug. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cesium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cesium

1861, in the meaning defined above

History and Etymology for cesium

New Latin, from Latin caesius bluish gray

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Last Updated

31 Aug 2018

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Time Traveler for cesium

The first known use of cesium was in 1861

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More Definitions for cesium

cesium

noun
ce·si·um
variants: or chiefly British caesium \ˈsē-zē-əm \

Medical Definition of cesium 

: a silver-white soft ductile element of the alkali metal group that is the most electropositive element known and that is used especially in photoelectric cells symbol Cs — see Chemical Elements Table

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More from Merriam-Webster on cesium

Spanish Central: Translation of cesium

Nglish: Translation of cesium for Spanish Speakers

Britannica.com: Encyclopedia article about cesium

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