francium
Collocations
5ADJ.
atomic, chemical, fewer
VERB + FRANCIUM
appears
FRANCIUM + NOUN
alkali, atoms, metals
PREP.
in, than
ADV.
perhaps
Definitions
noun
The chemical element (symbol Fr) with an atomic number of 87. It is an intensely radioactive alkali metal that is not found in nature.
The most elusive element of all, however, appears to be francium, which is so rare that it is thought that our entire planet may contain, at any given moment, fewer than twenty francium atoms.
A single atom of this element.
Notice that franciums are balanced without even thinking in moles, atoms, or whatever.
(a) Radons and poloniums are compared, (b) poloniums and astatines are compared and (c) radons and franciums are compared.
Thesaurus
Synonyms
noun — a radioactive element of the alkali-metal group discovered a
Antonyms
Idioms & Phrases
Example Bank
6The most elusive element of all, however, appears to be francium, which is so rare that it is thought that our entire planet may contain, at any given moment, fewer than twenty francium atoms.
WiktionaryNotice that franciums are balanced without even thinking in moles, atoms, or whatever.
Wiktionary(a) Radons and poloniums are compared, (b) poloniums and astatines are compared and (c) radons and franciums are compared.
WiktionaryLithium, sodium, potassium, rubidium, caesium and francium are alkali metals.
Tatoeba · #1555667At any given moment, there are perhaps eight francium atoms in the whole of the earth.
Tatoeba · #2136324Francium is a chemical element of the symbol Fr.
Tatoeba · #2754901