https://w3id.org/framester/conceptnet5/data/en/radium <https://w3id.org/framester/conceptnet5/schema/IsA> <https://w3id.org/framester/conceptnet5/data/en/radioactive_substance> <https://w3id.org/framester/conceptnet5/data/en/unalloyed_metal> <https://w3id.org/framester/conceptnet5/schema/RelatedTo> <https://w3id.org/framester/conceptnet5/cla/de.radium> risorse dalla linked data cloud