radonn.
/ˈreɪdɒn/, U.S. /ˈreɪˌdɑn/ Chemistry.
A short-lived radioactive chemical element, atomic number 86, which is a member of the group of noble gases and occurs naturally in trace amounts as a result of the decay of radium and other radioactive elements; (originally) spec. the longest-lived isotope, radon-222, which has a half-life of 3.82 days. Symbol Rn (originally †Ro). The three isotopes first discovered were originally named actinium emanation, radium emanation, and thorium emanation, and subsequently actinon (radon-219), radon (radon-222), and thoron (radon-220). The names emanation and niton were also proposed for the element (cf. emanation n. 2c, niton n.).
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the world > matter > chemistry > elements and compounds > metals > noble gases > radon > [noun]
niton1911
radon1918
1918 Jrnl. Chem. Soc. 114 ii. 306 Radium emanation is given the name Radon, Ro, which at once indicates its origin and its relationship to the argon group.
1920 Jrnl. Amer. Chem. Soc. 42 2206 The names ‘radium emanation’ , ‘actinium emanation’ and ‘thorium emanation’ have been shortened, respectively, to ‘radon’ , ‘actinon’ and ‘thoron’.
1927 Observer 3 Apr. 20/2 The Radium Institute sends radium, or rather radon, its active principle, to hospitals all over the country.
1938 R. W. Lawson tr. G. von Hevesy & F. A. Paneth Man. Radioactivity (ed. 2) xxiii. 227 The first five disintegration products of the gas radon are isotopes of the metals polonium, lead, bismuth, or thallium.
1977 Time 22 Aug. 8/2 The radon in these waters is supposed to be good for everything from paralysis to curvature of the spine.
1991 Green Mag. Guide to Home 1 iv. 144/1 The main factor affecting the level of radon in houses is the amount of uranium in the underlying ground.
2002 High Country News 25 Nov. 5/4 Cotter plans to use the soil to cover ‘beaches’ of dry tailings that release radon and must be sprayed to contain the dust.
Compounds
C1. General attributive.
radon gas n.
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1934 Science 17 Aug. Suppl. 8/2 Dr. Evans made his experiments merely to test his new method of detecting extremely minute amounts of radium and radon gas emitted by radium.
1992 Economist 29 Feb. 94/3 Other environmental hazards, such as radon gas in houses and cigarette smoke, pose far greater risks to health.
2000 A. Sayle Barcelona Plates 47 The urge to combat seeped up through the ground in these parts along with the radon gas.
C2.
radon seed n. a short tube containing radon, used (esp. formerly) in radiotherapy as a source of alpha radiation.
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the world > health and disease > healing > medical treatment > treatment by radiation > [noun] > source
radium plaque1919
seed1924
radon seed1925
radium bomb1929
bomb1930
teleradium1930
telecobalt1948
sealed source1962
1925 A. E. H. Pinch Clin. Index Radium Therapy 61 Treatment by the burying..of numerous unscreened radon ‘seeds’..will often prove effective.
1966 Henschke & Hilaris in G. H. Fletcher Textbk. Radiotherapy i. 43/1 Ninety radon seeds each 0·75 cm. were permanently implanted through 17 needles and the uterus was sutured over the implant.
1980 Radiology 134 497 Sixty-six patients..underwent radiation therapy. Three methods were used:..(b) a combination of conventional fractionation and radon seed implant.
This entry has been updated (OED Third Edition, June 2008; most recently modified version published online March 2022).
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n.1918