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

• 有毒的非金属元素，有多种同素异形体，稳定且有金属特性的灰色同素异形体用于光电池，其在亮处的导电性比在暗处好，见于硫化物矿石中。