ATOMIC NUMBER 87

 I. (noun) 

Sense 1

Meaning:

A radioactive element of the alkali-metal group discovered as a disintegration product of actinium

Synonyms:

atomic number 87; Fr; francium

Classified under:

Nouns denoting substances

Hypernyms ("atomic number 87" is a kind of...):

metal; metallic element (any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.)

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