Assertion: neptunium | /r/HasProperty | produced
Facets:
value: artificially
type: MANNER
Source sentences:
text: Neptunium, element 93 on the periodic table of elements, was the first transuranium element to be produced synthetically and the first actinide series transuranium element to be discovered.
text: It was once believed that neptunium could only be produced artificially, but it’s since been discovered in trace amounts in uranium ores, where its presence can be attributed to decay.