radon

ra·don   (rā'dŏn)    n.   Symbol Rn A colorless, radioactive, inert gaseous element formed by the radioactive decay of radium. It is used as a radiation source in radiotherapy and to produce neutrons for research. Its most stable isotope is Rn 222 with a half-life of 3.82 days. Atomic number 86; melting point -71°C; boiling point -61.8°C; specific gravity (solid) 4. See Table at element. [rad(ium) + -on2.]

Main Entry:	radon
Part of Speech:	n
Definition:	See radon gas

Main Entry: ra·don
Pronunciation: 'rA-dän
Function: noun
: a heavy radioactive gaseous element of the group of inert gases formed bydisintegration of radium and used similarly to radium in medicine —symbol Rn; called also radium emanation; —see ELEMENT table

radon ra·don (rā'dŏn)
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; melting point -71°C; boiling point -61.7°C; specific gravity (solid) 4.

radon   (rā'dŏn)  Pronunciation Key  Symbol Rn A colorless, odorless, radioactive element in the noble gas group. It is produced by the radioactive decay of radium and occurs in minute amounts in soil, rocks, and the air near the ground. Radon is used as a source of radiation for the treatment of cancer and other diseases. Its most stable isotope is Rn 222 with a half-life of 3.82 days. Atomic number 86; melting point -71°C; boiling point -61.8°C; specific gravity (solid) 4. See Periodic Table.