the spontaneous emission of radiation from atomic nuclei. The radiation can consist of alpha, beta, and gamma radiation
radioactivity in American English
(ˌreidiouækˈtɪvɪti)
noun
Physics & Chemistry
the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element
Also called: activity
Word origin
[1895–1900; radio- + activity]This word is first recorded in the period 1895–1900. Other words that entered Englishat around the same time include: Marxism, backstage, backwind, frame of reference, freewheelradio- is a combining form with the meanings “dealing with radiant energy” (radiometer), “employing or dealing with radio waves” (radioacoustics; radiolocation; radiotelephone), “emitting rays as a result of the breakup of atomic nuclei” (radioactive; radiocarbon), “characterized by, employing or dealing with such rays” (radiography; radiopaque; radiotherapy)
Examples of 'radioactivity' in a sentence
radioactivity
`Your first lesson on radioactivity ,' said Viktor, in English.
Robert Wilson BLOOD IS DIRT (2002)
Does dry cleaning get rid of radioactivity?
Times, Sunday Times (2007)
This could cause nuclear reactions to restart, creating further radioactivity.
Times, Sunday Times (2011)
Water comes out of the taps, and the tests show normal levels of radioactivity.
Times, Sunday Times (2015)
They were told that the suspects were in a hospital for radioactivity victims.
Times, Sunday Times (2017)
Burns are the most common injury caused by radioactivity.
Times, Sunday Times (2010)
Meteorites can be dated by testing its level of radioactivity.
canada.com (2004)
The natural radioactivity of the elements characteristic of the strata was weak.
The Times Literary Supplement (2015)
Her pioneering research on radioactivity made her the world's most famous female scientist.
Times, Sunday Times (2013)
There wasn't any radioactivity or relativity, extinction or evolution to muddle things up.
Times, Sunday Times (2009)
Guarding them and checking regularly for radioactivity costs taxpayers millions of pounds every year.