Category:Thallium

Thal"li*um, n. Etym: [nl., fr. Gr. green line in its spectrum.] (chem.)

Defn: a rare metallic element of the aluminium group found in some Minerals, as certain pyrites, and also in the lead-chamber deposit in The manufacture of sulphuric acid. It is isolated as a heavy, soft, Bluish white metal, easily oxidized in moist air, but preserved by Keeping under water. Symbol tl. Atomic weight 203.7.