Dictionary

ionium

noun io·ni·um \ī-ˈō-nē-əm\

Definition of IONIUM

:  a natural radioactive isotope of thorium having a mass number of 230

Origin of IONIUM

ion; from its ionizing action
First Known Use: 1907
Medical Dictionary

ionium

noun io·ni·um \ī-ˈō-nē-əm\

Medical Definition of IONIUM

:  a natural radioactive isotope of thorium having a mass number of 230

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