СЕЛЕН существительное

[Определение Wordnet: a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite)]

[Понятие РуТез: неметаллы]

[Понятие РуТез: селен]