Assertion: beryllium | /r/HasProperty | unique
Facets:
Source sentences:
text: Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons.
text: Beryllium is a unique metal that seems to naturally form into spheres, its natural unrefined state seems to be the most useful.
text: Beryllium is unique as being the only monoisotopic element with both an even number of protons and an odd number of neutrons.