- 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.
Origin of actinon
Also called actinium emanation.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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
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