ionium

American  

[ahy-oh-nee-uhm] / aɪˈoʊ ni əm /

noun

Chemistry.

1. a naturally occurring radioactive isotope of thorium. Io; 90; 230.

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ionium British  

/ aɪˈəʊnɪəm /

noun

1.  Io.  obsolete a naturally occurring radioisotope of thorium with a mass number of 230

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Etymology

Origin of ionium

First recorded in 1905–10; ion + -ium

Example Sentences

Then crusty old Elias Loomis pioneered in devising the basis for modern weather maps and Bertram Boltwood discovered ionium.

From Time Magazine Archive

An ionium collector, for which the radioactive material was kindly supplied by Mr. F. H. Glew, was used.

From South: the story of Shackleton's 1914-1917 expedition by Shackleton, Ernest Henry, Sir

Ballon’s first samples gave uranium atoms with a fair representation of ionium and thorium.

From Astounding Stories of Super-Science, March 1930 by Bates, Harry

Uranium X1, then, would have an atomic weight of 234 and that of ionium would be 230.

From A Brief Account of Radio-activity by Venable, Francis Preston

Further, it became clear from the investigation of uranium minerals that radium, polonium, actinium, and ionium originated from uranium.

From A Brief Account of Radio-activity by Venable, Francis Preston