noun
rubidium
roo-BID-ee-uhm
Rubidium (noun) means a soft, highly reactive metallic element with the symbol Rb and atomic number 37. Example: “Rubidium is a soft alkali metal.”
noun
1
A soft, highly reactive metallic element with the symbol Rb and atomic number 37.
"Rubidium is a soft alkali metal."
"The chemistry student wrote Rb next to the word rubidium on her periodic table."
"Rubidium reacts readily with other substances."
How to use rubidium
Learner’s notesIn plain EnglishThe name of the soft alkali metal with atomic number 37.
When to use it
A technical word from chemistry, used in science teaching and writing.
Memory tip
It is uncountable in most uses, so say rubidium is soft, not a rubidium is soft.
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Common pairings
rubidium atom
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_____ is a soft alkali metal.
Etymology
The German chemist R. W. Bunsen coined the name in 1861 from the Latin word rubidus, meaning red. It refers to the two red lines in the element's spectrum.
Rhymes for rubidium
See all rhymes for rubidium →Frequently asked questions
What is rubidium?
Rubidium is a chemical element with the symbol Rb and atomic number 37. It is a soft, very reactive metal in the alkali group.
Where does the word rubidium come from?
It comes from the Latin rubidus, meaning red, because the element's spectrum has two red lines. Bunsen coined it in 1861.
What is the symbol for rubidium?
The symbol is Rb.
What is the meaning of rubidium?
"rubidium" (noun) means a soft, highly reactive metallic element with the symbol Rb and atomic number 37.
