Radon
/ˈreɪ.dɒn/noun
A radioactive noble gas formed from the decay of radium.
Did you know?Radon was named from radium because it was first identified as a decay product of that element, and the name was later standardized when the gas’s isotopes were sorted out.
Etymological Timeline
1899-1900
French/English
radium emanation
“The gas was first described as an emanation released from radium.”
Early 20th century
English
radon
“A proposed name for the radioactive noble gas produced by radium decay.”
1918
English
radon
“The International Committee on Atomic Weights and later usage standardized radon as the name of the element.”
Modern English
English
radon
“The radioactive noble gas element with atomic number 86.”