thallium

[ thal-ee-uhm ]

noun

, Chemistry.

1. a soft, malleable, rare, bluish-white metallic element: used in the manufacture of alloys and, in the form of its salts, in rodenticides. : Tl; : 204.37; : 81; : 11.85 at 20°C.

thallium

/ ˈθælɪəm /

noun

1. a soft malleable highly toxic white metallic element used as a rodent and insect poison and in low-melting glass. Its compounds are used as infrared detectors and in photoelectric cells. Symbol: Tl; atomic no: 81; atomic wt: 204.3833; valency: 1 or 3; relative density: 11.85; melting pt: 304°C; boiling pt: 1473±10°C

thallium

/ thăl′ē-əm /

1. A soft, malleable, very poisonous metallic element that is used in photography, in making low-melting and highly refractive glass, and in treating skin infections. Atomic number 81; atomic weight 204.38; melting point 303.5°C; boiling point 1,457°C; specific gravity 11.85; valence 1, 3.
2. See Periodic Table

Word History and Origins

Origin of thallium¹

1860–65; < New Latin, equivalent to thall- (< Greek thallós green stalk) + -ium -ium; named after green line in its spectrum

Word History and Origins

Origin of thallium¹

C19: from New Latin, from Greek thallos a green shoot; referring to the green line in its spectrum

Example Sentences

Much of the thallium in the Baltic Sea, the largest human-induced hypoxic area on Earth, accumulates in the sediment thanks to abundant sulfide minerals.

From Science Daily

They precisely measured isotopes of the metal thallium trapped in the sediments, which indicate how much oxygen was dissolved in the global ocean at the time the sediments formed.

From Science Daily

Doctors later diagnosed her with thallium poisoning, a soft metal which dissolves in water and is odourless and tasteless.

From BBC

Lepidolite extraction and smelting produces toxic by-products like thallium and tantalum that cause severe water pollution, said Wu Wei, an assistant professor at Xiamen University.

From Reuters

In 2015, a female university student in Nagoya was convicted of attempting to murder two classmates with thallium while she was in high school.

From BBC