Assertion: radon | /r/HasProperty | fifth radioactive element
Facets:
value: after uranium
type: OTHER
value: after thorium
type: OTHER
value: by ernest rutherford
type: OTHER
value: after radium
type: OTHER
value: in 1899
type: TEMPORAL
value: after polonium
type: OTHER
Source sentences:
text: Radon was the fifth radioactive element to be discovered, in 1899 by Ernest Rutherford and Robert B. Owens at McGill University in Montreal, after uranium, thorium, radium, and polonium.
text: Radon was the fifth radioactive element to be discovered, after uranium, thorium, radium and polonium.