[ ak-tuh-non ]
/ ˈæk təˌnɒn /

noun Chemistry.

a chemically inert, gaseous, short-lived isotope of radon that is a member of the actinium series. Symbol: An; atomic number: 86; atomic weight: 219.



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Also called actinium emanation.

Origin of actinon

From New Latin, dating back to 1925–30; see origin at actinium, -on2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for actinon

/ (ˈæktɪˌnɒn) /


a radioisotope of radon that is a decay product of radium. Symbol: An or 219 Rn; atomic no: 86; half-life: 3.92s
another name for actinide

Word Origin for actinon

C20: New Latin, from actinium + -on
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012