Radon (Rn)
noble-gasGas
प्रमाणित अणुभार
[222]इलेक्ट्रॉन संरूपण
[Xe] 6s2 4f14 5d10 6p6द्रवणांक
-71.15 °Cउत्कलनांक
-61.7 °Cघनता
9.73 kg/m³ऑक्सिडीकरण अवस्था
0, +2, +6विद्युतऋणता (पॉलिंग)
उपलब्ध नाहीआयनीकरण ऊर्जा (पहिली)
10.7485 eVशोधाचे वर्ष
1900अणुत्रिज्या
उपलब्ध नाहीतपशील
Radon is a radioactive noble gas and the heaviest naturally occurring member of group 18. It is chemically inert compared with most elements, but its radioactivity makes it environmentally and medically important. Natural radon is produced mainly in uranium and thorium decay chains, especially as ²²²Rn from radium-226. Its gaseous form lets it migrate from rocks, soils, and building materials into air and enclosed spaces.
Radon is present in the atomosphere at very low concentrations. See Wikipedia for discussion of concentration. At ordinary temperatures radon is a colorless gas; when cooled below the freezing point, radon exhibits a brilliant phosphorescence which becomes yellow as the temperature is lowered and orange-red at the temperature of liquid air. It has been reported that fluorine reacts with radon, forming a fluoride. Radon clathrates have also been reported.
Radon was discovered by Friedrich Ernst Dorn, a German chemist, in 1900 while studying radium's decay chain. Originally named niton after the Latin word for shining, nitens, radon has been known as radon since 1923. Today, radon is still primarily obtained through the decay of radium. At normal room temperatures, radon is a colorless, odorless, radioactive gas. The most common forms of radon decay through alpha decay. Alpha decay usually isn't considered to be a great radiological hazard since the alpha particles produced by the decay are easily stopped. However, since radon is a gas, it is easily inhaled and living tissue is directly exposed to the radiation. Although it has a relatively short half-life, radon decays into longer lived, solid, radioactive elements which can collect on dust particles and be inhaled as well. For these reasons, there is some concern as to the amount of radon present within homes. Radon seeps into houses as a result of the decay of radium, thorium or uranium ores underground and varies greatly from location to location. On average, the earth's atmosphere is 0.0000000000000000001% radon.
When cooled to its solid state, radon glows yellow. The glow becomes orange-red as the temperature is lowered.
Radon's most stable isotope, radon-222, has a half-life of about 3.8 days. It decays into polonium-218 through alpha decay.
The name was derived from radium; called niton at first, from the Latin word nitens meaning shining.The element was discovered in 1900 by Dorn, who called it radium emanation. In 1908 Ramsay and Gray, who named it niton, isolated the element and determined its density, finding it to be the heaviest known gas. It is essentially inert and occupies the last place in the zero group of gases in the Periodic Table. Since 1923, it has been called radon.
Pure radon is a colorless, odorless, monatomic gas at ordinary temperature and pressure. It can be condensed at low temperature to a liquid and then a solid, but macroscopic handling is limited by intense radioactivity and radiolytic effects.
Radon has no broad commercial use. Historically, sealed radon sources were used in some radiotherapy practices before safer and more controllable radionuclides became preferred. It has also been used as a tracer in hydrology, geology, and atmospheric studies because it is continuously generated in rocks and has isotope-dependent decay times. Present use is mainly analytical or research-related, including calibration and environmental measurement work.
Small amounts of radon are sometimes used by hospitals to treat some forms of cancer. Radon fluoride (RnF) is the only confirmed compound of radon.
Radon is still produced for therapeutic use by a few hospitals by pumping it from a radium source and sealing it in minute tubes, called seeds or needles, for application to patient. This practice has been largely discontinued as hospitals can get the seeds directly from suppliers, who make up the seeds with the desired activity for the day of use.
Isotopes in Earth/Planetary Science
Both 220Rn and 222Rn (with half-lives of 56 s and 3.8 days, respectively) are used to study underground environmental and atmospheric gaseous-transport processes [568] United States Geological Survey. Resources on Isotopes-Periodic Table-Radon, U.S. Geological Survey (2014), Feb. 25; http://wwwrcamnl.wr.usgs.gov/isoig/period/rn_iig.html., [569] State of California Department of Conservation. Indoor Radon, State of California Department of Conservation (2017), April 8; http://www.consrv.ca.gov/CGS/minerals/hazardous_minerals/radon/Pages/index.aspx., [570] L. S. Quindos Poncela, C. Sainz Fernandez, I. Fuente Merino, J. L. Gutierrez Villanueva, A. Gonzalez Diez. Acta Geophysica.61, 848 (2013).. The interaction of radon with streams and rivers enables it to be used as a tracer in groundwater studies (Fig. IUPAC.86.1). 222Rn has a short residence time in streams and river channels, which leads to radon loss. As a result, if an area of a stream or river has a high concentration of radon, it suggests that there are local groundwater inputs [568] United States Geological Survey. Resources on Isotopes-Periodic Table-Radon, U.S. Geological Survey (2014), Feb. 25; http://wwwrcamnl.wr.usgs.gov/isoig/period/rn_iig.html., [569] State of California Department of Conservation. Indoor Radon, State of California Department of Conservation (2017), April 8; http://www.consrv.ca.gov/CGS/minerals/hazardous_minerals/radon/Pages/index.aspx., [570] L. S. Quindos Poncela, C. Sainz Fernandez, I. Fuente Merino, J. L. Gutierrez Villanueva, A. Gonzalez Diez. Acta Geophysica.61, 848 (2013).. In a deep (100 m) contaminated aquifer at a refinery site in Mexico, where the contaminated source was too deep to be directly accessible for sampling, Schubert et al. [571] M. Schubert, M. Balcazar, A. Lopez, P. Peña, J. H. Flores, K. Knöller. Isot. Environ. Health Stud.43, 215 (2007). collected groundwater samples from a few wells available at the site. They used the partitioning of the natural tracer 222Rn between uncontaminated groundwater and the NAPL (non-aqueous phase-liquid, such as oil, gasoline, and petroleum) source zone, and they were able to approximately identify the location of the NAPL source zone. As noted in Section 4.88.1, 222Rn has been used to quantify submarine groundwater discharge [572] R. N. Peterson, W. C. Burnett, M. Taniguchi, J. Chen, I. R. Santos, T. Ishitobi. J. Geophys. Res.113, C09021 (2008)..
Isotopes in Geochronology
222Rn has been used as a tool to date groundwater in combination with other isotopes or elemental ratios (i.e. helium/radon and xenon/radon amount ratios) [568] United States Geological Survey. Resources on Isotopes-Periodic Table-Radon, U.S. Geological Survey (2014), Feb. 25; http://wwwrcamnl.wr.usgs.gov/isoig/period/rn_iig.html., [574] T. F. Kraemer, D. P. Genereux. “Applications of uranium- and thorium-series radionuclides in catchment hydrology studies”, in Isotope Tracers in Catchment Hydrology, C. Kendall, J. J. McDonnell (Eds.), Elsevier, Amsterdam (1998)..
Radon is the least chemically studied noble gas because its isotopes are radioactive and available only in small amounts. The most established chemistry involves strong oxidizing and fluorinating conditions, with radon difluoride (RnF₂) reported as a radon compound. Ionic or complex fluoride species have been inferred in matrix and tracer experiments, but many details remain uncertain. Oxidation states above 0 are possible in principle, yet radon chemistry is much less developed than xenon chemistry.
See more information at the Radon compound page.
Radon is hazardous chiefly because inhaled radioactive decay products can lodge in the respiratory tract and irradiate tissue with alpha particles. The risk depends strongly on isotope, concentration, ventilation, exposure time, and the behavior of short-lived progeny such as polonium isotopes. Radon is also an asphyxiant like other gases if present at very high concentrations, but radiation exposure is the practical concern.
Care must be taken in handling radon, as with other radioactive materials. The main hazard is from inhalation of the element and its solid daughters which are collected on dust in the air. Good ventilation should be provided where radium, thorium, or actinium is stored to prevent build-up of the element. Radon build-up is a health consideration in uranium mines. Recently radon build-up in homes has been a concern. Many deaths from lung cancer are caused by radon exposure. In the U.S. it is recommended that remedial action be taken if the air in homes exceeds 4 pCi/l.
Radon forms naturally where uranium or thorium decay occurs in minerals and soils. Being a gas, it can diffuse through pore spaces, dissolve to some extent in groundwater, and enter buildings through cracks or service penetrations. Outdoors it is usually diluted rapidly, while enclosed or poorly ventilated spaces can accumulate higher concentrations. Its decay products attach to aerosols and surfaces, changing their mobility and exposure pathways.
Radon is not traded as a normal industrial commodity. It is generated continuously by decay of radium in sealed sources or collected in small quantities for specialized calibration and research needs. Supply is constrained less by elemental scarcity than by radiological controls, isotope half-lives, and the limited demand for handling the gas. Most practical applications that once used radon have been replaced by other radionuclides, electronic instruments, or direct environmental monitoring methods.
Formed from the decay of radium in the earths crust.
Radon has no stable isotopes, so it cannot accumulate over geological or cosmic timescales. In nature it appears only as a transient daughter in decay chains of long-lived heavy nuclides such as uranium and thorium. In extraterrestrial materials, any radon would likewise be short-lived and locally produced rather than primordial.
- Radon is the densest noble gas encountered naturally on Earth.
- The isotope ²²²Rn has a half-life of about 3.8 days, long enough for migration through soil.
- Radon was once called niton, a name reflected in the old symbol Nt.
- Indoor radon levels often vary with season, pressure differences, and building ventilation.
- Radon measurements can reveal subsurface gas movement and some groundwater interactions.
प्रतिमा
गुणधर्म
भौतिक
- सहसंयुजी त्रिज्या
- 150 pm सर्व घटकांच्या सहसंयुजी त्रिज्या ची तुलना करा →
- व्हॅन डर वाल्स त्रिज्या
- 220 pm सर्व घटकांच्या व्हॅन डर वाल्स त्रिज्या ची तुलना करा →
- घनता
- 9.73 kg/m³ सर्व घटकांच्या घनता ची तुलना करा →
- STP येथे अवस्था
- वायू सर्व घटकांच्या STP येथे अवस्था ची तुलना करा →
- द्रवणांक
- -71.15 °C सर्व घटकांच्या द्रवणांक ची तुलना करा →
- उत्कलनांक
- -61.7 °C सर्व घटकांच्या उत्कलनांक ची तुलना करा →
- उष्णता चालकता
- 0.004 W/(m·K) सर्व घटकांच्या उष्णता चालकता ची तुलना करा →
- विशिष्ट उष्माधारकता
- 0.094 J/(g·K) सर्व घटकांच्या विशिष्ट उष्माधारकता ची तुलना करा →
- मोलर उष्माधारकता
- 20.786 J/(mol·K) सर्व घटकांच्या मोलर उष्माधारकता ची तुलना करा →
- स्फटिक संरचना
- पृष्ठकेंद्रित घनीय सर्व घटकांच्या स्फटिक संरचना ची तुलना करा →
रासायनिक
- विद्युतऋणता (ॲलन)
- 2.6
- इलेक्ट्रॉन आसक्ती
- -0.7 eV (नकारात्मक मूल्य — अणूने अतिरिक्त इलेक्ट्रॉन बांधण्याचा अंदाज नाही)
- आयनीकरण ऊर्जा (पहिली)
- 10.7485 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पहिली) ची तुलना करा →
- आयनीकरण ऊर्जा (दुसरी)
- 18.990065 eV सर्व घटकांच्या आयनीकरण ऊर्जा (दुसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (तिसरी)
- 29.400101 eV सर्व घटकांच्या आयनीकरण ऊर्जा (तिसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (चौथी)
- 36.900127 eV सर्व घटकांच्या आयनीकरण ऊर्जा (चौथी) ची तुलना करा →
- आयनीकरण ऊर्जा (पाचवी)
- 52.900182 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पाचवी) ची तुलना करा →
- ऑक्सिडीकरण अवस्था
- 0, +2, +6 सर्व घटकांच्या ऑक्सिडीकरण अवस्था ची तुलना करा →
- संयुजा इलेक्ट्रॉन
- 8 सर्व घटकांच्या संयुजा इलेक्ट्रॉन ची तुलना करा →
- इलेक्ट्रॉन संरूपण
- [Xe] 6s2 4f14 5d10 6p6
उष्मागतिक
- त्रिक बिंदू (तापमान)
- -71 °C
- त्रिक बिंदू (दाब)
- 5.1e+4 Pa
- क्रांतिक बिंदू (तापमान)
- 104 °C
- क्रांतिक बिंदू (दाब)
- 6.28e+6 Pa
- द्रवण उष्मा
- 0.03109292 eV सर्व घटकांच्या द्रवण उष्मा ची तुलना करा →
- बाष्पीभवन उष्मा
- 0.16582889 eV सर्व घटकांच्या बाष्पीभवन उष्मा ची तुलना करा →
- अणूकरण उष्मा
- 0 eV
केंद्रकीय
- प्रोटॉन
- 86 सर्व घटकांच्या प्रोटॉन ची तुलना करा →
- न्यूट्रॉन
- 136 सर्व घटकांच्या न्यूट्रॉन ची तुलना करा →
- ज्ञात समस्थानिके
- 39 सर्व घटकांच्या ज्ञात समस्थानिके ची तुलना करा →
- स्थिर समस्थानिके
- 0 सर्व घटकांच्या स्थिर समस्थानिके ची तुलना करा →
- वस्तुमानांक (सर्वाधिक स्थिर)
- 222
- सर्वाधिक स्थिर समस्थानिक
- Rn-222
- शोधाचे वर्ष
- 1900
विपुलता
- विपुलता (पृथ्वीचे कवच)
- 4e-13 mg/kg सर्व घटकांच्या विपुलता (पृथ्वीचे कवच) ची तुलना करा →
- विपुलता (महासागर)
- 6 × 10−16 mg/L सर्व घटकांच्या विपुलता (महासागर) ची तुलना करा →
स्फटिक संरचना
उपलब्ध नाही
इलेक्ट्रॉन संरचना
- प्रत्येक कवचातील इलेक्ट्रॉन
- 2, 8, 18, 32, 18, 8 सर्व घटकांच्या प्रत्येक कवचातील इलेक्ट्रॉन ची तुलना करा →
ओळखचिन्हे
- CAS क्रमांक
- 10043-92-2 सर्व घटकांच्या CAS क्रमांक ची तुलना करा →
- टर्म चिन्ह
- 1S0
- InChI
- InChI=1S/Rn
- InChI की
- SYUHGPGVQRZVTB-UHFFFAOYSA-N
इलेक्ट्रॉन संरूपण मोजलेले
Rn: 4f¹⁴ 5d¹⁰ 6s² 6p⁶[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶अणुप्रतिमान
समस्थानिकांमुळे न्यूट्रॉन संख्या, वस्तुमान आणि स्थैर्य बदलते — विद्युतदृष्ट्या उदासीन अणूचे इलेक्ट्रॉन संरूपण बदलत नाही.
योजनात्मक अणुप्रतिमान, प्रमाणानुसार नाही.
अणूची विशिष्ट ओळख
उत्सर्जन / शोषण वर्णपट
समस्थानिक वितरण
स्थिर समस्थानिके नाहीत.
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य |
|---|---|---|---|
| 194 किरणोत्सारी | १९४.००६१४४ ± ०.००००१८ | उपलब्ध नाही | 780 us |
| 217 किरणोत्सारी | २१७.००३९२८ ± ०.०००००४५ | उपलब्ध नाही | 593 us |
| 199 किरणोत्सारी | १९८.९९८३९ ± ०.००००६८ | उपलब्ध नाही | 590 ms |
| 214 किरणोत्सारी | २१३.९९५३६३ ± ०.०००००९९ | उपलब्ध नाही | 259 ns |
| 205 किरणोत्सारी | २०४.९९१७१९ ± ०.००००५४ | उपलब्ध नाही | 170 सेकंद |
अवस्था / स्थिती
कारण: उत्कलनांकापेक्षा (-61.7 °C) 86.7 °C अधिक
योजनात्मक, प्रमाणानुसार नाही
अवस्थांतर बिंदू
अवस्थांतर ऊर्जा
द्रवणांकावर 1 mol वितळवण्यासाठी आवश्यक ऊर्जा
उत्कलनांकावर 1 mol चे बाष्पीभवन करण्यासाठी आवश्यक ऊर्जा
घनता
प्रमाणित परिस्थितीत
सध्याच्या T येथे आदर्श वायू नियमाने अंदाजित
प्रगत
अणुवर्णपट
86 पैकी 10 दाखवले आहेत. आयनाच्या विद्युतभारानुसार चढत्या क्रमाने मांडलेले.
वर्णरेषांचा संग्रह ?
| आयन | विद्युतभार | एकूण वर्णरेषा | संक्रमण संभाव्यता | पातळ्यांची नामांकने |
|---|---|---|---|---|
| Rn I | 0 | 67 | 0 | 10 |
ऊर्जा पातळ्यांचा संग्रह ?
| आयन | विद्युतभार | पातळ्या |
|---|---|---|
| Rn I | 0 | 127 |
| Rn II | +1 | 3 |
| Rn III | +2 | 2 |
| Rn IV | +3 | 2 |
| Rn V | +4 | 2 |
| Rn VI | +5 | 2 |
| Rn VII | +6 | 2 |
| Rn VIII | +7 | 2 |
| Rn IX | +8 | 2 |
| Rn X | +9 | 2 |
घन अवस्थेसाठी स्फटिक संरचनेची माहिती उपलब्ध नाही
स्फटिक संरचना: fcc
संयुगे
समस्थानिके (5)
Thirty-nine isotopes are known. Radon-222 is the most common. It has a half-life of 3.823 days and is an alpha emitter. It is estimated that every square mile of soil to a depth of 6 inches contains about 1 g of radium, which releases radon in tiny amounts into the atmosphere. Radon gas can collect in buildings, creating a health risk. The Environmental Protection Agency estimates that responsible for an estimated 20,000 lung cancer deaths each year. More on radon and health. Radon is present in some spring waters, such as those at Hot Springs, Arkansas.
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य | क्षय प्रकार | |
|---|---|---|---|---|---|
| 194 किरणोत्सारी | १९४.००६१४४ ± ०.००००१८ | उपलब्ध नाही | 780 us | α ≈100%β+ ? | |
| 217 किरणोत्सारी | २१७.००३९२८ ± ०.०००००४५ | उपलब्ध नाही | 593 us | α =100% | |
| 199 किरणोत्सारी | १९८.९९८३९ ± ०.००००६८ | उपलब्ध नाही | 590 ms | α ≈100%β+ ? | |
| 214 किरणोत्सारी | २१३.९९५३६३ ± ०.०००००९९ | उपलब्ध नाही | 259 ns | α =100% | |
| 205 किरणोत्सारी | २०४.९९१७१९ ± ०.००००५४ | उपलब्ध नाही | 170 सेकंद | β+ =75.4±0.9%α =24.6±0.9% |
विस्तारित गुणधर्म
सहसंयुजी त्रिज्या (विस्तारित)
- सहसंयुजी त्रिज्या (प्युक्को)
- 142 pm
- सहसंयुजी त्रिज्या (प्युक्को, दुहेरी बंध)
- 145 pm
- सहसंयुजी त्रिज्या (प्युक्को, तिहेरी बंध)
- 133 pm
व्हॅन डर वाल्स त्रिज्या
- Truhlar
- 220 pm
- Alvarez
- 240 pm
- UFF
- 476.5 pm
- MM3
- 243 pm
अणुत्रिज्या आणि धात्विक त्रिज्या
- अणुत्रिज्या (राह्म)
- 243 pm
क्रमांकन मापनपट्ट्या
- Mendeleev
- 117
- Pettifor
- 6
- Glawe
- 6
विद्युतऋणता मापनपट्ट्या
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 4
ध्रुवणक्षमता आणि अपस्करण
- द्विध्रुव ध्रुवणक्षमता
- 35 a.u.
- द्विध्रुव ध्रुवणक्षमता (अनिश्चितता)
- 2 a.u.
- C₆ (Gould–Bučko)
- 408 Ha·Bohr6
राजवायूंचे गुणधर्म
| HALOGENS | RnF2 |
अवस्थांतरे आणि अपरूपे
| द्रवणांक | 202.15 K |
| उत्कलनांक | 211.45 K |
| क्रांतिक बिंदू (तापमान) | 377.15 K |
| क्रांतिक बिंदू (दाब) | 6.28 MPa |
ऑक्सिडीकरण अवस्थांचे वर्ग
प्रगत संदर्भ माहिती
परिरक्षण स्थिरांक (15)
| n | कक्षिका | σ |
|---|---|---|
| 1 | s | 1.6659 |
| 2 | p | 4.562 |
| 2 | s | 22.5864 |
| 3 | d | 13.4027 |
| 3 | p | 23.7194 |
| 3 | s | 24.9149 |
| 4 | d | 38.0572 |
| 4 | f | 37.6688 |
| 4 | p | 36.6988 |
| 4 | s | 35.85 |
समस्थानिक क्षय प्रकार (59)
| समस्थानिक | मोड | तीव्रता |
|---|---|---|
| 193 | A | 100% |
| 194 | A | 100% |
| 194 | B+ | — |
| 195 | A | 100% |
| 196 | A | 100% |
| 196 | B+ | — |
| 197 | A | 100% |
| 197 | B+ | — |
| 198 | A | 93% |
| 198 | B+ | — |
क्ष-किरण प्रकीर्णन गुणक (516)
| ऊर्जा (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 2.83964 |
| 10.1617 | — | 3.21791 |
| 10.3261 | — | 3.64656 |
| 10.4931 | — | 4.05083 |
| 10.6628 | — | 4.4288 |
| 10.8353 | — | 4.83437 |
| 11.0106 | — | 5.24445 |
| 11.1886 | — | 5.68932 |
| 11.3696 | — | 6.15277 |
| 11.5535 | — | 6.62072 |
अतिरिक्त माहिती
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4×10-13 milligrams per kilogram
संदर्भ (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
6×10-16 milligrams per liter
संदर्भ (1)
संदर्भ
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Radon.
The element property data was retrieved from publications.