Assertion: astatine | /r/HasProperty | isolated as element
Facets:
value: by emilio serge
type: OTHER
value: by dale r. corson
type: OTHER
value: in 1940
type: TEMPORAL
value: by ross mackenzie
type: OTHER
Source sentences:
text: Astatine was isolated as an element by Dale R. Corson, Ross MacKenzie and Emilio Serge in 1940.