radon

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astatine (At)
Next: francium (Fr) →
English Wikipedia article on Radon

Contraction of radium emanation, since the element appears in the radioactive decay of radium. By surface analysis, radio- +‎ -on (“suffix for noble gases”).

• enPR: rā'dŏn, IPA^(key): /ˈɹeɪdɒn/

• Audio (Southern England):

  (file)

• Audio (General American):

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radon (uncountable)

2. The chemical element (symbol Rn, formerly Ro) with atomic number 86. It is an odorless, colorless, chemically inert but radioactive noble gas.
3. Radon-222 (22286Rn), the most stable isotope of said element.

The isotopes ²²²Rn, ²²⁰Rn, and ²¹⁹Rn were discovered independently, and were called radon (Rn), thoron (Tn), and actinon (An) respectively. In 1957, it was finally decided that the name radon should refer to the element in general, regardless of isotope. Thoron still survives as a name for ²²⁰Rn today; actinon is mostly obsolete, because ²¹⁹Rn is short-lived.^[1]

• actinon
• radium emanation

• Radon on the British Royal Society of Chemistry's online periodic table

• Ardon, Daron, rando, Andro, Ronda, Norad, NORAD, Doran, andro, Drona, andor, norad, Nador, and/or, Nardo, adorn, andro-

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astaat (At)
Next: frankium, ekasesium (obsolete) (Fr) →

• Audio:

  (file)

• Hyphenation: ra‧don

radon (uncountable)

1. radon

• edelgas

From Spanish radón.

• IPA^(key): /radon/ [ra.ð̞õn]

• Audio:

  (file)

• Rhymes: -adon, -on
• Hyphenation: ra‧don

radon inan

1. radon

• “radon”, in Euskaltzaindiaren Hiztegia [Dictionary of the Basque Academy] (in Basque), Euskaltzaindia [Royal Academy of the Basque Language]

Other scripts
Cyrillic	радон
Roman

Borrowed from Russian радон (radon).

radon

1. radon

• Mirjejev, V. A.; Usejinov, S. M. (2002), Ukrajinsʹko-krymsʹkotatarsʹkyj slovnyk [Ukrainian – Crimean Tatar Dictionary]‎^[1], Simferopol: Dolya, →ISBN
• “radon”, in Luğatçıq (in Russian)

• IPA^(key): [ˈradon]
• IPA^(key): [ˈradoːn]

radon m inan

1. radon

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: francium (Fr) →

From Latin radium +‎ -on.

radon n (singular definite radonet, not used in plural form)

1. radon

• “radon” in Den Danske Ordbog

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astaat (At)
Next: francium (Fr) →

• IPA^(key): /ˈraː.dɔn/

• Audio:

  (file)

radon n (uncountable, no diminutive)

1. radon

• IPA^(key): /ˈradon/

• Audio:

  (file)

• Rhymes: -adon
• Syllabification: ra‧don

radon

1. accusative singular of rado

From English radon.

• IPA^(key): /ˈrɑ(ː)don/, [ˈrɑ̝(ː)do̞n]
• Rhymes: -ɑdon
• Syllabification^(key): ra‧don
• Hyphenation^(key): ra‧don

radon

1. radon

• raadon

• “radon”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎^[2] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 3 July 2023

• andro-

• IPA^(key): /ʁa.dɔ̃/

• Audio (France (Brétigny-sur-Orge)):

  (file)

• Rhymes: -ɔ̃

radon m (uncountable)

1. radon

• “radon”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

• rando

radon m (uncountable)

1. radon

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← asztácium (At)
Next: francium (Fr) →

• IPA^(key): [ˈrɒdon]
• Hyphenation: ra‧don
• Rhymes: -on

radon (usually uncountable, plural radonok)

1. radon

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: fransín (Fr) →

radon n (genitive singular radons, no plural)

1. radon (chemical element)

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astato (At)
Next: francio (Fr) →

• IPA^(key): /ˈra.don/
• Rhymes: -adon
• Hyphenation: rà‧don

radon m (invariable)

1. (chemistry) radon

• Andro, Nardò, Rando, andro-, andrò, nardo, ronda

radon

1. Rōmaji transcription of ラドン

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astatium (At)
Next: francium (Fr) →

• (Classical Latin) IPA^(key): [ˈra.dɔn]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈraː.don]

radon n (genitive radī); second declension

1. radon

Second-declension noun (neuter, Greek-type).

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astatin (At)
Next: fransium (Fr) →

From English radon.

• IPA^(key): [radɔn], [redɔn]
• Rhymes: -dɔn, -ɔn

radon

1. radon (chemical element)

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: franċju (Fr) →

Borrowed from Italian radon.

• IPA^(key): /ˈraː.dɔn/
• Rhymes: -aːdɔn

radon m

1. (chemistry) radon (chemical element)

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: frans (Fr) →

Learned borrowing from New Latin radon.

• IPA^(key): /ˈra.dɔn/

• Audio 1:

  (file)

• Audio 2:

  (file)

• Rhymes: -adɔn
• Syllabification: ra‧don

radon m inan (related adjective radonowy)

1. radon (chemical element (symbol Rn, formerly Ro) with atomic number 86; a colorless, odorless, chemically inert but radioactive noble gas)

• “radon”, in Polish dictionaries at PWN‎^[3] (in Polish)
• radon in PWN's encyclopedia

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← poloniu (Po)
Next: franciu (Fr) →

Borrowed from French radon.

radon n (uncountable)

1. radon (chemical element)

• “radon”, in DEX online—Dicționare ale limbii române (Dictionaries of the Romanian language) (in Romanian), 2004–2026

radon m inan (Cyrillic spelling радон)

1. radon

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: francij (Fr) →

• IPA^(key): /ráːdɔn/, /radóːn/

radọ̑n or radón m inan

1. radon

The diacritics used in this section of the entry are non-tonal. If you are a native tonal speaker, please help by adding the tonal marks.

Masculine inan., hard o-stem
nominative	rádon
genitive	rádona
	singular
nominative (imenovȃlnik)	rádon
genitive (rodȋlnik)	rádona
dative (dajȃlnik)	rádonu
accusative (tožȋlnik)	rádon
locative (mẹ̑stnik)	rádonu
instrumental (orọ̑dnik)	rádonom

• “radon”, in Slovarji Inštituta za slovenski jezik Frana Ramovša ZRC SAZU (in Slovene), 2014–2026

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astat (At)
Next: francium (Fr) →

• IPA^(key): /raˈdoːn/

• Audio:

  (file)

radon n (uncountable)

1. radon

• “radon”, in Svensk ordbok [Dictionary of Swedish] (in Swedish)
• “radon”, in Svenska Akademiens ordlista [Wordlist of the Swedish Academy] (in Swedish)
• “radon”, in Svenska Akademiens ordbok [Dictionary of the Swedish Academy] (in Swedish)
• Svensk MeSH

• andor, donar, ordna, rodna

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astatin (At)
Next: fransiyum (Fr) →

Borrowed from French radon.

• Audio:

  (file)

radon (definite accusative radonu, plural radonlar)

1. radon

• “radon”, in Turkish dictionaries, Türk Dil Kurumu

Chemical element (edit)
Rn Atomic number 86 radon
Classification data Period 6 Group 18 Block p-block Class noble gas
Previous: ← astatin (At)
Next: ffranciwm (Fr) →

Borrowed from English radon.

• (North Wales) IPA^(key): /ˈradɔn/
• (South Wales) IPA^(key): /ˈra(ː)dɔn/
• Rhymes: -adon

radon m (uncountable, not mutable)

1. radon

• R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “radon”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies