radon (redirected from radium emanation)

radon /ra·don/ (ra´don) a gaseous radioactive element, at. no. 86, symbol Rn, resulting from decay of radium.

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ra·don (rdn)

n. Symbol Rn

A radioactive, largely inert gaseous element formed by the radioactive decay of radium and used as a radiation source in radiotherapy and research; its most stable isotope is Rn 222 with a half-life of 3.82 days. Atomic number 86.

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radon,

n A byproduct of radium decomposition used in radiotherapy.

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radon

a chemical element, atomic number 86, atomic weight 222, symbol Rn. See Table 6. Radon is a colorless, gaseous, radioactive element produced by the disintegration of radium.

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radon 222Ra Public health A natural radioactive gaseous element, atomic number 86; atomic weight, 211.4 in the 238U → 206Pb decay chain; radon has a T_1⁄2 of 3.8 days, decays into 2 solid α particle-emitting daughters; radon exposure carries a relative risk of 12.7 for lung CA in non-smoking uranium miners and an ↑ risk of childhood CA, myelogenous leukemia, renal cell carcinoma, melanoma, prostate CA. See Radionics, Radium Dial Company.