ru·​bid·​i·​um | \ rü-ˈbi-dē-əm How to pronounce rubidium (audio) \

Definition of rubidium

: a soft silvery metallic element of the alkali metal group that reacts violently with water and bursts into flame spontaneously in air — see Chemical Elements Table

Examples of rubidium in a Sentence

Recent Examples on the Web However, the trap that holds the rubidium atoms can be tuned to efficiently suck energy out of them. Chris Lee, Ars Technica, 7 Feb. 2022 Physicist Ron Folman of Ben-Gurion University of the Negev in Israel and his colleagues re-created the Stern-Gerlach experiment using not individual atoms but a cloud of rubidium atoms. Davide Castelvecchi, Scientific American, 8 Feb. 2022 In a media statement, the company stated that their rubidium atomic clock would deliver a frequency stability of about 2x10-14 over averaging intervals of 10,000 seconds. Jennifer Kite-powell, Forbes, 18 Sep. 2021 The team loaded 200 million rubidium atoms into their vacuum chamber and passed laser light through all the optics components, making the light collide with the atoms. Karmela Padavic-callaghan, Wired, 7 Sep. 2021 In that vacuum chamber, 18 tiny collections of rubidium atoms — about 10,000 to a group — are arranged in a line and cooled to phenomenally low temperatures, a fraction of a degree above absolute zero. Quanta Magazine, 7 Sep. 2021 Atoms of rubidium, a heavy cousin of the more familiar lithium and sodium, are appealing because their internal quantum states can be set and controlled by light. Gabriel Popkin, Science | AAAS, 3 June 2021 The physicists used rubidium atoms that had been cooled to temperatures about a millionth of a degree Kelvin above absolute zero as a starting point for their plasma—an extremely cold temperature instead of the extremely hot one inside the sun. Karmela Padavic-callaghan, Wired, 17 Mar. 2021 The researchers reported that the rubidium atoms spent, on average, 0.61 milliseconds inside the barrier, in line with Larmor clock times theoretically predicted in the 1980s. Quanta Magazine, 20 Oct. 2020 See More

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

First Known Use of rubidium

1861, in the meaning defined above

History and Etymology for rubidium

New Latin, from Latin rubidus red, from rubēre

Learn More About rubidium

Time Traveler for rubidium

Time Traveler

The first known use of rubidium was in 1861

See more words from the same year

Dictionary Entries Near rubidium




See More Nearby Entries 

Statistics for rubidium

Cite this Entry

“Rubidium.” Dictionary, Merriam-Webster, Accessed 13 Aug. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for rubidium


ru·​bid·​i·​um | \ rü-ˈbid-ē-əm How to pronounce rubidium (audio) \

Medical Definition of rubidium

: a soft silvery metallic element that decomposes water with violence and bursts into flame spontaneously in air symbol Rb — see Chemical Elements Table

More from Merriam-Webster on rubidium Encyclopedia article about rubidium


Test Your Vocabulary

Commonly Confused Words Quiz

  • vector image of a face with thought expression
  • I went to the ______ store to buy a birthday card.
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!