Radon (Rn)
noble-gasGas
मानक परमाणु भार
[222]इलेक्ट्रॉन विन्यास
[Xe] 6s2 4f14 5d10 6p6गलनांक
-71.15 °Cक्वथनांक
-61.7 °Cघनत्व
9.73 kg/m³ऑक्सीकरण अवस्थाएँ
0, +2, +6विद्युतऋणात्मकता (पॉलिंग)
उपलब्ध नहींआयनन ऊर्जा (प्रथम)
10.7485 eVखोज का वर्ष
1900परमाणु त्रिज्या
उपलब्ध नहींविवरण
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.
चित्र
गुण
भौतिक
- सहसंयोजक त्रिज्या
- 150 pm सभी तत्वों की सहसंयोजक त्रिज्या की तुलना करें →
- वान डर वाल्स त्रिज्या
- 220 pm सभी तत्वों की वान डर वाल्स त्रिज्या की तुलना करें →
- घनत्व
- 9.73 kg/m³ सभी तत्वों की घनत्व की तुलना करें →
- STP पर प्रावस्था
- गैस सभी तत्वों की STP पर प्रावस्था की तुलना करें →
- गलनांक
- -71.15 °C सभी तत्वों की गलनांक की तुलना करें →
- क्वथनांक
- -61.7 °C सभी तत्वों की क्वथनांक की तुलना करें →
- तापीय चालकता
- 0.004 W/(m·K) सभी तत्वों की तापीय चालकता की तुलना करें →
- विशिष्ट ऊष्मा धारिता
- 0.094 J/(g·K) सभी तत्वों की विशिष्ट ऊष्मा धारिता की तुलना करें →
- मोलर ऊष्मा धारिता
- 20.786 J/(mol·K) सभी तत्वों की मोलर ऊष्मा धारिता की तुलना करें →
- क्रिस्टल संरचना
- फलक-केंद्रित घनीय सभी तत्वों की क्रिस्टल संरचना की तुलना करें →
रासायनिक
- विद्युतऋणात्मकता (ऐलन)
- 2.6
- इलेक्ट्रॉन बंधुता
- -0.7 eV (ऋणात्मक मान — परमाणु द्वारा अतिरिक्त इलेक्ट्रॉन बांधने की भविष्यवाणी नहीं)
- आयनन ऊर्जा (प्रथम)
- 10.7485 eV सभी तत्वों की आयनन ऊर्जा (प्रथम) की तुलना करें →
- आयनन ऊर्जा (द्वितीय)
- 18.990065 eV सभी तत्वों की आयनन ऊर्जा (द्वितीय) की तुलना करें →
- आयनन ऊर्जा (तृतीय)
- 29.400101 eV सभी तत्वों की आयनन ऊर्जा (तृतीय) की तुलना करें →
- आयनन ऊर्जा (चतुर्थ)
- 36.900127 eV सभी तत्वों की आयनन ऊर्जा (चतुर्थ) की तुलना करें →
- आयनन ऊर्जा (पंचम)
- 52.900182 eV सभी तत्वों की आयनन ऊर्जा (पंचम) की तुलना करें →
- ऑक्सीकरण अवस्थाएँ
- 0, +2, +6 सभी तत्वों की ऑक्सीकरण अवस्थाएँ की तुलना करें →
- संयोजकता इलेक्ट्रॉन
- 8 सभी तत्वों की संयोजकता इलेक्ट्रॉन की तुलना करें →
- इलेक्ट्रॉन विन्यास
- [Xe] 6s2 4f14 5d10 6p6
ऊष्मागतिक
- त्रिक बिंदु (तापमान)
- -71 °C
- त्रिक बिंदु (दाब)
- 5.1e+4 Pa
- क्रांतिक बिंदु (तापमान)
- 104 °C
- क्रांतिक बिंदु (दाब)
- 6.28e+6 Pa
- गलन ऊष्मा
- 0.03109292 eV सभी तत्वों की गलन ऊष्मा की तुलना करें →
- वाष्पन ऊष्मा
- 0.16582889 eV सभी तत्वों की वाष्पन ऊष्मा की तुलना करें →
- परमाणुकरण ऊष्मा
- 0 eV
नाभिकीय
- प्रोटॉन
- 86 सभी तत्वों की प्रोटॉन की तुलना करें →
- न्यूट्रॉन
- 136 सभी तत्वों की न्यूट्रॉन की तुलना करें →
- ज्ञात समस्थानिक
- 39 सभी तत्वों की ज्ञात समस्थानिक की तुलना करें →
- स्थिर समस्थानिक
- 0 सभी तत्वों की स्थिर समस्थानिक की तुलना करें →
- द्रव्यमान संख्या (सबसे स्थिर)
- 222
- सबसे स्थिर समस्थानिक
- Rn-222
- खोज का वर्ष
- 1900
प्रचुरता
- प्रचुरता (भूपर्पटी)
- 4e-13 mg/kg सभी तत्वों की प्रचुरता (भूपर्पटी) की तुलना करें →
- प्रचुरता (महासागर)
- 6 × 10−16 mg/L सभी तत्वों की प्रचुरता (महासागर) की तुलना करें →
क्रिस्टल संरचना
उपलब्ध नहीं
इलेक्ट्रॉनिक संरचना
- प्रति कोश इलेक्ट्रॉन
- 2, 8, 18, 32, 18, 8 सभी तत्वों की प्रति कोश इलेक्ट्रॉन की तुलना करें →
पहचानकर्ता
- CAS संख्या
- 10043-92-2 सभी तत्वों की CAS संख्या की तुलना करें →
- टर्म प्रतीक
- 1S0
- InChI
- InChI=1S/Rn
- InChI कुंजी
- SYUHGPGVQRZVTB-UHFFFAOYSA-N
इलेक्ट्रॉन विन्यास मापित
Rn: 4f¹⁴ 5d¹⁰ 6s² 6p⁶[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶परमाणु मॉडल
समस्थानिक न्यूट्रॉन की संख्या, द्रव्यमान और स्थिरता बदलते हैं — उदासीन परमाणु का इलेक्ट्रॉन विन्यास नहीं।
सांकेतिक परमाणु मॉडल, वास्तविक अनुपात में नहीं।
परमाणु पहचान-चिह्न
उत्सर्जन / अवशोषण स्पेक्ट्रम
समस्थानिक वितरण
कोई स्थिर समस्थानिक नहीं है।
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु |
|---|---|---|---|
| 194 रेडियोधर्मी | 194.006144 ± 0.000018 | उपलब्ध नहीं | 780 us |
| 217 रेडियोधर्मी | 217.003928 ± 0.0000045 | उपलब्ध नहीं | 593 us |
| 199 रेडियोधर्मी | 198.99839 ± 0.000068 | उपलब्ध नहीं | 590 ms |
| 214 रेडियोधर्मी | 213.995363 ± 0.0000099 | उपलब्ध नहीं | 259 ns |
| 205 रेडियोधर्मी | 204.991719 ± 0.000054 | उपलब्ध नहीं | 170 सेकंड |
प्रावस्था / अवस्था
कारण: क्वथनांक (-61.7 °C) से 86.7 °C अधिक
सांकेतिक, वास्तविक अनुपात में नहीं
प्रावस्था संक्रमण बिंदु
संक्रमण ऊर्जाएँ
गलनांक पर 1 mol को पिघलाने के लिए आवश्यक ऊर्जा
क्वथनांक पर 1 mol को वाष्पित करने के लिए आवश्यक ऊर्जा
घनत्व
मानक परिस्थितियों में
वर्तमान T पर आदर्श गैस नियम से अनुमानित
उन्नत
परमाणु स्पेक्ट्रम
86 में से 10 दिखाए जा रहे हैं। आयन के आवेश के अनुसार आरोही क्रम में व्यवस्थित।
उपलब्ध स्पेक्ट्रमी रेखा डेटा ?
| आयन | आवेश | कुल रेखाएँ | संक्रमण प्रायिकताएँ | स्तर पदनाम |
|---|---|---|---|---|
| Rn I | 0 | 67 | 0 | 10 |
उपलब्ध ऊर्जा स्तर डेटा ?
| आयन | आवेश | स्तर |
|---|---|---|
| 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 |
ठोस प्रावस्था के लिए क्रिस्टल संरचना का डेटा उपलब्ध नहीं है
क्रिस्टल संरचना: fcc
यौगिक
समस्थानिक (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.
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु | क्षय का प्रकार | |
|---|---|---|---|---|---|
| 194 रेडियोधर्मी | 194.006144 ± 0.000018 | उपलब्ध नहीं | 780 us | α ≈100%β+ ? | |
| 217 रेडियोधर्मी | 217.003928 ± 0.0000045 | उपलब्ध नहीं | 593 us | α =100% | |
| 199 रेडियोधर्मी | 198.99839 ± 0.000068 | उपलब्ध नहीं | 590 ms | α ≈100%β+ ? | |
| 214 रेडियोधर्मी | 213.995363 ± 0.0000099 | उपलब्ध नहीं | 259 ns | α =100% | |
| 205 रेडियोधर्मी | 204.991719 ± 0.000054 | उपलब्ध नहीं | 170 सेकंड | β+ =75.4±0.9%α =24.6±0.9% |
विस्तृत गुण
सहसंयोजक त्रिज्याएँ (विस्तृत)
- सहसंयोजक त्रिज्या (प्यूक्को)
- 142 pm
- सहसंयोजक त्रिज्या (प्यूक्को, द्विबंध)
- 145 pm
- सहसंयोजक त्रिज्या (प्यूक्को, त्रिबंध)
- 133 pm
वान डर वाल्स त्रिज्याएँ
- Truhlar
- 220 pm
- Alvarez
- 240 pm
- UFF
- 476.5 pm
- MM3
- 243 pm
परमाणु और धात्विक त्रिज्याएँ
- परमाणु त्रिज्या (राह्म)
- 243 pm
संख्यांकन मापक्रम
- Mendeleev
- 117
- Pettifor
- 6
- Glawe
- 6
विद्युतऋणात्मकता मापक्रम
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 4
ध्रुवणीयता और परिक्षेपण
- द्विध्रुव ध्रुवणीयता
- 35 a.u.
- द्विध्रुव ध्रुवणीयता (अनिश्चितता)
- 2 a.u.
- C₆ (Gould–Bučko)
- 408 Ha·Bohr6
उत्कृष्ट गैसों के गुण
| HALOGENS | RnF2 |
प्रावस्था संक्रमण और अपररूप
| गलनांक | 202.15 K |
| क्वथनांक | 211.45 K |
| क्रांतिक बिंदु (तापमान) | 377.15 K |
| क्रांतिक बिंदु (दाब) | 6.28 MPa |
ऑक्सीकरण अवस्था की श्रेणियाँ
उन्नत संदर्भ डेटा
परिरक्षण स्थिरांक (15)
| n | कक्षक | 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 के 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+ | — |
एक्स-रे 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 डेटा
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.