放ほう射しゃ性せい元げん素そほうしゃせいげんそMeanings1nounradioactive element; radioelementphysicsPhysics term for an element whose atoms have unstable nuclei and emit radiation.ウランは代だい表ひょう的てきな放ほう射しゃ性せい元げん素そです。Uranium is a typical radioactive element.放ほう射しゃ性せい元
