Assertion: protactinium | /r/HasProperty | preserved for some time
Facets:
value: in air
type: LOCATION
Source sentences:
text: Protactinium is a metal with silvery-gray luster that is preserved for some time in air.
text: Protactinium is a metal with silvery-gray luster that is preserved for some time in air.
text: Protactinium is a metal with silvery-gray luster that is preserved for some time in air.   
text: Protactinium is a metal with silvery-gray luster that is preserved for some time in air.