caesium

/ ˈsiːzɪəm /

noun

a ductile silvery-white element of the alkali metal group that is the most electropositive metal. It occurs in pollucite and lepidolite and is used in photocells. The radioisotope caesium-137 , with a half-life of 30.2 years, is used in radiotherapy. Symbol: Cs; atomic no: 55; atomic wt: 132.90543; valency: 1; relative density: 1.873; melting pt: 28.39±0.01°C; boiling pt: 671°C

Like caesium, it is precipitated with platinic chloride, and in the ordinary course of work would be weighed as potassium.

Lithia and fluorine are each present to the extent of about 5%; rubidium and caesium are sometimes present in small amounts.

It led Bunsen himself almost immediately to the isolation of two new elements of the alkali group, caesium and rubidium.

This residue consists of sodium, potassium and lithium chlorides, with small quantities of caesium and rubidium chlorides.

Caesium sulphate, Cs2SO4, may be prepared by dissolving the hydroxide or carbonate in sulphuric acid.

April 19, 2024tortuous

[tawr-choo-uhs ]

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