| atomic number 34 
 
 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)
 • Syn:
 selenium, Se
 • Hypernyms:
 chemical element, element, antioxidant
 • Substance Holonyms:
 pyrite, iron pyrite, fool's gold
 
 
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