: a metallic chemical element that is the most electropositive element known and that is used in photoelectric cells, in atomic clocks, and as a component of drilling fluid see Chemical Elements Table
Examples of cesium in a Sentence
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The current gold standard for ultra-precise timekeeping is the cesium atomic clock, where the tiny and fixed energy transitions of the atom’s electrons are used to keep track of time.
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Shi En Kim, Smithsonian Magazine, 23 Sep. 2024
Scientists use a laser to bathe a cesium atom with photons.
—Quanta Magazine, 4 Sep. 2024
Since 2014, the primary current standard in the US—a cesium fountain clock located at the NIST—has been capable of keeping time with an uncertainty of 1 second in 300 million years.
—Andrew Paul, Popular Science, 5 Sep. 2024
Nuclear energy is generated by splitting uranium, leaving behind dangerous radioactive products, such as cesium and strontium, that must be isolated for centuries.
—Ernest Moniz, Foreign Affairs, 17 Oct. 2011
See all Example Sentences for cesium 
Shi En Kim, Smithsonian Magazine, 23 Sep. 2024
Scientists use a laser to bathe a cesium atom with photons.
—Quanta Magazine, 4 Sep. 2024
Since 2014, the primary current standard in the US—a cesium fountain clock located at the NIST—has been capable of keeping time with an uncertainty of 1 second in 300 million years.
—Andrew Paul, Popular Science, 5 Sep. 2024
Nuclear energy is generated by splitting uranium, leaving behind dangerous radioactive products, such as cesium and strontium, that must be isolated for centuries.
—Ernest Moniz, Foreign Affairs, 17 Oct. 2011
See all Example Sentences for cesium
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“Cesium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cesium. Accessed 1 Oct. 2024.
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Medical Definition
cesium
noun
ce·si·um
variants
or chiefly British caesium
: 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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