n. 硒

[化] 硒Se

[医] 硒(34号元素)

[ noun ]
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)
<noun.substance>

Selenium \Se*le"ni*um\, n. [NL., from Gr. selh`nh the moon. So
called because of its chemical analogy to tellurium (from L.
tellus the earth), being, as it were, a companion to it.]
(Chem.)
A nonmetallic element of the sulphur group of atomic number
34, analogous to sulphur in its compounds. It is found in
small quantities with sulphur and some sulphur ores, and
obtained in the free state as a dark reddish powder or
crystalline mass, or as a dark metallic-looking substance. It
exhibits under the action of light a remarkable variation in
electric conductivity, and is used in certain electric
apparatus. Symbol Se. Atomic weight 78.96.