ionium

[ ahy-oh-nee-uhm ]

noun

, Chemistry.

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

ionium

/ aɪˈəʊnɪəm /

noun

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

Word History and Origins

Origin of ionium¹

First recorded in 1905–10; ion + -ium

Word History and Origins

Origin of ionium¹

C20: from New Latin, from ion + -ium

Example Sentences

Ionium expels an alpha particle and becomes radium, which is a bivalent element resembling barium belonging to the second group.

From Project Gutenberg