Thallium

['θælɪəm]

Definition

(noun.) a soft grey malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores.

Checked by Lilith--From WordNet

Definition

(n.) 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.

Checked by Debs

Definition

n. a metal closely resembling lead in colour and softness but slightly heavier first discovered in 1861 and so called from the presence of an intense green line in the spectrum of the flame in which it is volatilised.—adjs. Thall′ic Thall′ious.

Edited by Della