Assertion: neptunium | /r/HasProperty | rare
Facets:
value: very
type: DEGREE
value: for a long time
type: TEMPORAL
value: in nature
type: LOCATION
Source sentences:
text: It is extremely rare in nature, existing in only trace amounts in ores which contain uranium.
text: Neptunium was once a very rare element, but it can now be somewhat easily produced in a nuclear reactor.
text: NEPTUNIUM used as a noun is very rare.
text: It used to be very rare and for a long time, people thought that neptunium didn’t exist in nature and was a man-made element, but we now know that very small amounts can be found in the Earth’s crust.
text: Neptunium was once a very rare element, but it can now be somewhat easily produced in a nuclear reactor.
text: Neptunium was once a very rare element, but it can now be somewhat easily produced in a nuclear reactor.