Assertion: protactinium | /r/HasProperty | radioactive element
Facets:
value: highly
type: DEGREE
Source sentences:
text: Protactinium is a radioactive element predicted to exist in 1871 by Mendeleev, although it was not discovered until 1917 or isolated until 1934.
text: Protactinium is a radioactive element predicted to exist in 1871 by Mendeleev, although it was not discovered until 1917 or isolated until 1934.
text: Protactinium is a radioactive element that is long-lived.
text: Protactinium is highly radioactive element.