Iodine (I)
halogenSolid
Peso atomico standard
126,90447 uConfigurazione elettronica
[Kr] 5s2 4d10 5p5Punto di fusione
113,7 °CPunto di ebollizione
184,4 °CDensità
4930 kg/m³Stati di ossidazione
−1, +1, +2, +3, +4, +5, +6, +7Elettronegatività (Pauling)
2,66Energia di ionizzazione (1ª)
10,451236 eVAnno della scoperta
1811Raggio atomico
140 pmDettagli
Iodine is a heavy halogen and the least abundant stable halogen in Earth’s crust. The element occurs naturally as iodide and iodate rather than as free I₂. It is chemically less electronegative and less strongly oxidizing than bromine or chlorine, and it forms a wide range of covalent, ionic, and polyiodide species. Iodine is an essential trace element for vertebrates because thyroid hormones contain iodine atoms.
Iodine is a bluish-black, lustrous solid, volatizing at ordinary temperatures into a blue-violet gas with an irritating odor; it forms compounds with many elements, but is less active than the other halogens, which displace it from iodides. Iodine exhibits some metallic-like properties. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide to form beautiful purple solutions. It is only slightly soluble in water.
The name derives from the Greek iodes for "violet" because of its violet vapours. Iodine was discovered in seaweed by the French chemist Bernard Courtois in 1811, and named by the French chemist Louis-Joseph Gay-Lussac, when he proved it was an element in 1814.
Iodine was discovered by the French chemist Barnard Courtois in 1811. Courtois was extracting sodium and potassium compounds from seaweed ash. Once these compounds were removed, he added sulfuric acid (H2SO4) to further process the ash. He accidentally added too much acid and a violet colored cloud erupted from the mass. The gas condensed on metal objects in the room, creating solid iodine. Today, iodine is chiefly obtained from deposits of sodium iodate (NaIO3) and sodium periodate (NaIO4) in Chile and Bolivia. Trace amounts of iodine are required by the human body. Iodine is part of thyroxin, a hormone produced by the thyroid gland that controls the body's rate of physical and mental development. A lack of iodine can also cause a goiter, a swelling of the thyroid gland. Iodine is added to salt (iodized salt) to prevent these diseases.
From the Greek word iodes, violet. Discovered by Courtois in 1811, Iodine, a halogen, occurs sparingly in the form of iodides in sea water from which it is assimilated by seaweeds, Chilean saltpeter, nitrate-bearing earth (known as caliche), brines from old sea deposits, and in brackish waters from oil and salt wells.
Pure iodine is a dark gray to purple-black crystalline solid at ordinary temperature. It has a metallic-looking luster and a distinctive sharp odor. It sublimes readily to a violet vapor, and the vapor recondenses as shiny crystals on cooler surfaces.
The largest uses of iodine are in compounds rather than in elemental I₂. Iodinated contrast agents are important in X-ray and computed-tomography imaging. Iodine compounds are used in antiseptics, disinfectants, animal feed supplements, and pharmaceuticals. Silver iodide, AgI, has been used in cloud-seeding and photographic materials. Iodine chemistry is also used in polarizing films for liquid-crystal displays and in analytical titrations based on iodine and iodide equilibria.
Iodine is used as a test for starch and turns a deep blue when it comes in contact with it. Potassium iodide (KI) is used to make photographic film and, when mixed with iodine in alcohol, as an antiseptic for external wounds. A radioactive isotope of iodine, iodine-131, is used to treat some diseases of the thyroid gland.
Care should be taken in handling and using iodine. It can burn the skin and damage the eyes and mucous membranes. Pure iodine is poisonous if ingested.
Iodine compounds are important in organic chemistry and very useful in medicine. Iodides, and thyroxine which contains iodine, are used internally in medicine, and as a solution of KI and iodine in alcohol is used for external wounds. Potassium iodide finds use in photography. The deep blue color with starch solution is characteristic of the free element.
Isotopes in Forensic Science and Anthropology
131I (with a half-life of about 8 days) and 129I are both fission products; 129I is a long-lived fission product with a half-life of 1.7×107 years that can be helpful in the detection of the movement of radiation after a radioactive event, such as occurred at the Japanese reactors at Fukushima. In nuclear reactors and weapons tests, uranium and plutonium undergo fission processes in which one of the fission products is the long-lived isotope 129I. This isotope has been used as a groundwater tracer to determine evidence of nuclear fission, and it can also be tracked in rainwater as evidence of a fission event in the air (weapons explosion; Fig. IUPAC.53.1) [390] D. Elmore, H. E. Gove, R. Ferraro, L. R. Kilius, H. W. Lee, K. H. Chang, R. P. Beukens, A. E. Litherland, C. J. Russo, K. H. Purser, M. T. Murrell, R. C. Finkel. Nature286, 138 (1980)., [391] G. Snyder, U. Fehn. Nucl. Instrum. Methods Phys. Res. B223, 579 (2004)., [392] G. Snyder, A. Aldahan, G. Possnert. Geochem. Geophys.11, Q04010 (2010)..
Isotopes in Geochronology
Natural cosmogenic 129I enters groundwater and other terrestrial environments from the atmosphere and then decays to 129Xe. The isotope-amount ratio n(129I)/n(127I) can be used as a clock to estimate time since cosmogenic 129I entered the system. The amount of product 129Xe in such cases is too small to measure; however, excess quantities of 129Xe can be found in meteorites and other very old samples that contained extinct primordial 129I. Younger water bodies also can be differentiated from older water bodies by determining the amount of anthropogenic 129I released since the 1960s from sources such as nuclear bomb tests [393] P. H. Santschi, J. E. Moran, S. Oktay, E. Hoehn, P. Sharma. “129Iodine: a new tracer for surface water/groundwater interaction”, in International Symposium on Isotope Techniques in Water Resources Development and Management., [394] G. M. Raisbeck, F. Yiou, Z. Q. Zhou, L. R. Kilius. J. Marine Syst.6, 561 (1995)..
Isotopes in Medicine
125I, which has a half-life of about 59 days, is used encapsulated in radiotherapy to target and treat sites of cancerous tumors [395] V. R. Narra, R. W. Howell, R. S. Harapanhalli, K. S. Sastry, D. V. Rao. J. Nucl. Med.33, 2196 (1992).. 120gI (with a half-life of 1.36 h), where the “g” indicates ground state, and 124I (with a half-life of 100 h) are radioactive isotopes that emit positrons and they are used in quantitative, diagnostic imaging of the body using positron emission tomography (PET) [383] A. Hohn, H. H. Coenen, S. M. Qaim. Appl. Radiat. Isot.49, 1493 (1998)., [384] H. Herzog, S. M. Qaim, L. Tellmann, S. Spellerberg, D. Kruecker, H. H. Coenen. Eur. J. Nucl. Med. Mol. Imaging33, 1249 (2006)., [385] A. Hohn, B. Scholten, H. H. Coenen, S. M. Qaim, Appl. Radiat. Isot.49, 93 (1998)., [387] M. L. Firouzbakht, D. J. Schlyer, R. D. Finn, G. Laguzzi, A. P. Wolf. Nucl. Instr. Methods Phys. Res. B79, 909 (1993)., [388] H. Herzog, L. Tellman, S. M. Qaim, S. Spellerberg, A. Schmid, H. H. Coenen. Appl. Radiat. Isot.56, 673 (2002)., [389] F. T. Lee, C. Hall, A. Rigopoulos, J. Zweit, K. Pathmaraj, G. J. O’Keefe, F. E. Smyth, S. Welt, L. J. Old, A. M. Scott. J. Nucl. Med.42, 764 (2001).. 123I and 131I (with half-lives of 0.55 day and 8 days, respectively) are used with single-photon emission computed spectroscopy (SPECT) for basic three-dimensional imaging [386] T. Kakavand, M. Sadeghi, K. K. Moghaddam, S. S. Bonab, B. Fateh. Iran. J. Radiat. Res.5, 207 (2008)., [395] V. R. Narra, R. W. Howell, R. S. Harapanhalli, K. S. Sastry, D. V. Rao. J. Nucl. Med.33, 2196 (1992).. Radioactive iodine isotopes are produced from radioactive tellurium isotope.
Iodine commonly shows oxidation states −1, 0, +1, +3, +5, and +7. Hydrogen iodide, HI, and iodide salts contain I⁻ and are readily oxidized compared with chloride and bromide analogues. Iodine forms interhalogens such as iodine monochloride, ICl, and iodine pentafluoride, IF₅. Important oxoacids and salts include iodic acid, HIO₃, iodates, and periodates derived from periodic acid, HIO₄ or H₅IO₆. Polyiodides such as triiodide, I₃⁻, give the intense starch-iodine color reaction.
See more information at the Iodine compound page.
Elemental iodine is irritating to skin, eyes, and the respiratory tract, and its vapor can be harmful in poorly ventilated spaces. Concentrated iodide, iodate, or iodine preparations can disturb thyroid function, while trace intake is biologically necessary. Radioisotopes require isotope-specific control; iodine-131 is a beta and gamma emitter that concentrates in the thyroid and is a significant nuclear-medicine and contamination hazard.
Care should be taken in handling and using iodine, as contact with the skin can cause lesions; iodine vapor is intensely irritating to the eyes and mucus membranes. The maximum allowable concentration of iodine in air should not exceed 1 mg/m3 (8-hour time-weighted average - 40-hour).
Iodine is mobile in the environment because iodide, iodate, organoiodine compounds, and volatile iodine species interconvert in seawater, soils, sediments, and the atmosphere. The oceans are the main surface reservoir, and marine biological activity contributes to atmospheric iodine compounds. In soils, retention depends strongly on organic matter, redox conditions, and mineral surfaces. Iodine availability influences deficiency risk in inland food chains.
Commercial iodine is recovered mainly from iodine-rich underground brines and from caliche nitrate deposits, where iodate minerals occur with nitrate salts. Production is geographically concentrated, making supply sensitive to brine chemistry, mining practice, and co-product economics. Demand is driven by medical imaging agents, pharmaceuticals, nutrition, and industrial chemicals. Recycling occurs in some iodinated process streams and contrast-agent manufacture, but dispersed uses are difficult to recover.
Ultrapure iodine can be obtained from the reaction of potassium iodide with copper sulfate. Several other methods of isolating the element are known.
Iodine is a relatively rare element in cosmic material. Its single stable isotope, ¹²⁷I, is produced by neutron-capture processes in previous generations of stars. In the Solar System it is depleted in many rocky materials because iodine is moderately volatile and easily redistributed into fluids or gases. The extinct radionuclide ¹²⁹I is used in cosmochemistry to study early Solar System timing.
- Iodine was discovered from seaweed ash during saltpeter production in the early nineteenth century.
- Starch forms a deep blue complex with polyiodide, not with isolated iodide ion.
- Most naturally occurring iodine is the single stable isotope ¹²⁷I.
- Iodine sublimes noticeably at room temperature, although it also has an ordinary liquid phase above its melting point.
- Iodized salt usually contains iodide or iodate salts, not elemental iodine.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 140 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 139 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 198 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Densità
- 4930 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0257 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 113,7 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 184,4 °C Confronta Punto di ebollizione di tutti gli elementi →
- Capacità termica specifica
- 0,214 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 54,43 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Ortorombica Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 2,66 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 2,359
- Affinità elettronica
- 3,059 eV
- Energia di ionizzazione (1ª)
- 10,451236 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 19,131326 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 29,570102 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 40,357139 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 51,520177 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- −1, +1, +2, +3, +4, +5, +6, +7 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 7 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Kr] 5s2 4d10 5p5
Termodinamiche
- Punto triplo (temperatura)
- 113,6 °C
- Punto triplo (pressione)
- 1,211e+4 Pa
- Punto critico (temperatura)
- 546 °C
- Calore di fusione
- 0,16085402 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 0,21661398 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 0,64714722 eV
- Calore di atomizzazione
- 1,566047 eV
- Entalpia di atomizzazione
- 1,106462 eV
Nucleari
- Protoni
- 53 Confronta Protoni di tutti gli elementi →
- Neutroni
- 74 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 42 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 1 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- I-127
- Anno della scoperta
- 1811
Abbondanza
- Abbondanza (crosta terrestre)
- 0,45 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 0,06 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 772 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 18, 7 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7553-56-2 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 2P°3/2
- InChI
- InChI=1S/I
- Chiave InChI
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N
Configurazione elettronica Misurato
I: 4d¹⁰ 5s² 5p⁵[Kr] 4d¹⁰ 5s² 5p⁵1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁵Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 127 Stabile | 126,9044719 ± 0,0000039 | 100,0000% | Stabile |
Fase / Stato
Motivo: 88,7 °C sotto il punto di fusione (113,7 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Avanzate
Spettri atomici
Sono visualizzati 10 di 53. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| I I | 0 | 1432 | 417 | 1432 |
| I II | +1 | 126 | 0 | 122 |
| I III | +2 | 76 | 0 | 0 |
| I IV | +3 | 47 | 0 | 0 |
| I V | +4 | 4 | 0 | 0 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| I I | 0 | 229 |
| I II | +1 | 315 |
| I III | +2 | 116 |
| I IV | +3 | 61 |
| I V | +4 | 54 |
| I VI | +5 | 40 |
| I VII | +6 | 25 |
| I VIII | +7 | 36 |
| I IX | +8 | 2 |
| I X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| -1 | 6 | N/D | 220.00000000000003 pm |
| +5 | 3 | N/D | 44 pm |
| +5 | 6 | N/D | 95 pm |
| +7 | 4 | N/D | 42 pm |
| +7 | 6 | N/D | 53 pm |
Composti
Isotopi (1)
Thirty isotopes are recognized. Only one stable isotope, 127I is found in nature. The artificial radioisotope 131I, with a half-life of 8 days, has been used in treating the thyroid gland. The most common compounds are the iodides of sodium and potassium (KI) and the iodates (KIO3). Lack of iodine is the cause of goiter.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 127 Stabile | 126,9044719 ± 0,0000039 | 100,0000% | Stabile | stable |
Righe spettrali
Sono visualizzati 50 di 474. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 511.92792 nm | 120000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).7p 2[1]* | Misurata | NIST | |
| 740.20433 nm | 98000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).7d 2[4] | Misurata | NIST | |
| 661.96418 nm | 88000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).8d 2[4] | Misurata | NIST | |
| 746.89862 nm | 87000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).7d 2[4] | Misurata | NIST | |
| 723.78303 nm | 68000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).5f 2[4]* | Misurata | NIST | |
| 714.20318 nm | 53000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).7d 2[3] | Misurata | NIST | |
| 658.3733 nm | 48000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6f 2[4]* | Misurata | NIST | |
| 633.78649 nm | 44000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[3] | Misurata | NIST | |
| 619.1891 nm | 36000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).9d 2[4] | Misurata | NIST | |
| 712.20331 nm | 33000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).7d 2[3] | Misurata | NIST | |
| 514.55362 nm | 26000 | I I | emission | 5s2.5p4.(3P<1>).6s 2[1] → 5s2.5p4.(3P<1>).7p 2[1]* | Misurata | NIST | |
| 741.0472 nm | 25000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[4] → 5s2.5p4.(3P<2>).6f 2[5]* | Misurata | NIST | |
| 656.64687 nm | 23000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).8d 2[4] | Misurata | NIST | |
| 633.94468 nm | 22000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[3] | Misurata | NIST | |
| 722.72727 nm | 22000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).5f 2[3]* | Misurata | NIST | |
| 716.47586 nm | 21000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).7d 2[3] | Misurata | NIST | |
| 698.6488 nm | 20000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[4] → 5s2.5p4.(3P<2>).7f 2[5]* | Misurata | NIST | |
| 621.3101 nm | 19000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).9d 2[4] | Misurata | NIST | |
| 608.24072 nm | 18000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<1>).6p 2[2]* | Misurata | NIST | |
| 624.4475 nm | 17000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).7f 2[4]* | Misurata | NIST | |
| 631.31292 nm | 17000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[0] | Misurata | NIST | |
| 589.39929 nm | 16000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<1>).6p 2[1]* | Misurata | NIST | |
| 666.20777 nm | 15000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).8d 2[3] | Misurata | NIST | |
| 712.0036 nm | 15000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).7d 2[1] | Misurata | NIST | |
| 666.10964 nm | 14000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).9s 2[2] | Misurata | NIST | |
| 741.64587 nm | 14000 | I I | emission | 5s2.5p4.(3P<2>).5d 2[1] → 5s2.5p4.(3P<2>).5f 2[2]* | Misurata | NIST | |
| 595.6854 nm | 13000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).9d 2[3] | Misurata | NIST | |
| 598.4862 nm | 13000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).9d 2[2] | Misurata | NIST | |
| 637.16776 nm | 12000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[3] | Misurata | NIST | |
| 486.23094 nm | 11000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).7p 2[3]* | Misurata | NIST | |
| 491.69357 nm | 11000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).7p 2[2]* | Misurata | NIST | |
| 520.41202 nm | 11000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).7p 2[1]* | Misurata | NIST | |
| 629.39502 nm | 11000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<0>).6p 2[1]* | Misurata | NIST | |
| 633.0376 nm | 11000 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[2] | Misurata | NIST | |
| 523.45653 nm | 10000 | I I | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).7p 2[3]* | Misurata | NIST | |
| 533.82 nm | 10000 | I II | emission | 5s2.5p3.(2D*).6s 3D* → 5s2.5p3.(2D*).6p 3F | Misurata | NIST | |
| 562.569 nm | 10000 | I II | emission | 5s2.5p3.(4S*).6s 3S* → 5s2.5p3.(4S*).6p 3P | Misurata | NIST | |
| 707.78407 nm | 9700 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).7d 2[1] | Misurata | NIST | |
| 598.4207 nm | 8900 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).9d 2[3] | Misurata | NIST | |
| 742.00062 nm | 8300 | I I | emission | 5s2.5p4.(3P<2>).5d 2[4] → 5s2.5p4.(3P<2>).6f 2[4]* | Misurata | NIST | |
| 596.8258 nm | 7900 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).10d 2[4] | Misurata | NIST | |
| 698.97761 nm | 7800 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).9s 2[2] | Misurata | NIST | |
| 658.05101 nm | 7600 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6f 2[3]* | Misurata | NIST | |
| 673.20067 nm | 7600 | I I | emission | 5s2.5p4.(3P<2>).5d 2[1] → 5s2.5p4.(3P<2>).6f 2[3]* | Misurata | NIST | |
| 595.4372 nm | 6700 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).9d 2[3] | Misurata | NIST | |
| 741.1195 nm | 6700 | I I | emission | 5s2.5p4.(3P<2>).5d 2[1] → 5s2.5p4.(3P<2>).5f 2[3]* | Misurata | NIST | |
| 656.08006 nm | 6600 | I I | emission | 5s2.5p4.(3P<2>).6p 2[3]* → 5s2.5p4.(3P<2>).8d 2[2] | Misurata | NIST | |
| 723.49797 nm | 6600 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).5f 2[4]* | Misurata | NIST | |
| 633.35136 nm | 6300 | I I | emission | 5s2.5p4.(3P<2>).6p 2[2]* → 5s2.5p4.(3P<2>).8d 2[1] | Misurata | NIST | |
| 723.17992 nm | 6200 | I I | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).5f 2[3]* | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 133 pm
- Raggio covalente (Pyykkö, legame doppio)
- 129 pm
- Raggio covalente (Pyykkö, legame triplo)
- 125 pm
- Raggio covalente (Bragg)
- 140 pm
Raggi di van der Waals
- Bondi
- 198 pm
- Batsanov
- 210 pm
- Alvarez
- 204 pm
- UFF
- 450 pm
- MM3
- 236 pm
- Dreiding
- 415 pm
- Rowland–Taylor
- 203 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 238 pm
- Raggio metallico (C12)
- 139 pm
Scale di numerazione
- Mendeleev
- 109
- Pettifor
- 97
- Glawe
- 99
Scale di elettronegatività
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 7
- Robles–Bartolotti
- 6
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 32,9 a.u.
- Polarizzabilità dipolare (inc.)
- 1,3 a.u.
- C₆
- 385 Ha·Bohr6
- C₆ (Gould–Bučko)
- 389 Ha·Bohr6
Affinità chimica
- Affinità protonica
- 608,2 kJ/mol
- Basicità in fase gassosa
- 583,5 kJ/mol
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 60
- Rischio relativo di approvvigionamento
- 7
- Distribuzione delle riserve
- 67
- Stabilità politica (principale produttore)
- 68
- Stabilità politica (principale detentore di riserve)
- 68
Transizioni di fase e allotropi
| Punto di fusione | 386,85 K |
| Punto di ebollizione | 457,55 K |
| Punto critico (temperatura) | 819,15 K |
| Punto triplo (temperatura) | 386,75 K |
| Punto triplo (pressione) | 12,11 kPa |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (11)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,0609 |
| 2 | p | 4,1526 |
| 2 | s | 13,933 |
| 3 | d | 14,0993 |
| 3 | p | 18,1586 |
| 3 | s | 18,2126 |
| 4 | d | 32,066 |
| 4 | p | 28,9704 |
| 4 | s | 27,7028 |
| 5 | p | 41,3885 |
Dettaglio dei raggi cristallini (5)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| -1 | VI | 206 | Ahrens (1952) ionic radius, | |
| 5 | IIIPY | 58 | ||
| 5 | VI | 109 | ||
| 7 | IV | 56 | ||
| 7 | VI | 67 |
Modalità di decadimento degli isotopi (82)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 106 | A | — |
| 107 | A | — |
| 108 | A | 99,5% |
| 108 | p | 0,5% |
| 108 | B+ | — |
| 108 | B+p | — |
| 109 | p | 100% |
| 109 | A | 0% |
| 110 | B+ | 83% |
| 110 | A | 17% |
Fattori di diffusione dei raggi X (508)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 7,8167 |
| 10,1617 | — | 7,56781 |
| 10,3261 | — | 7,32685 |
| 10,4931 | — | 7,08081 |
| 10,6628 | — | 6,8332 |
| 10,8353 | — | 6,78435 |
| 11,0106 | — | 6,80888 |
| 11,1886 | — | 7,27334 |
| 11,3696 | — | 7,86775 |
| 11,5535 | — | 8,52786 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.5×10-1 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
6×10-2 milligrams per liter
Riferimenti (1)
Sources
Sources of this element.
Ultrapure iodine can be obtained from the reaction of potassium iodide with copper sulfate. Several other methods of isolating the element are known.
Riferimenti (1)
- [6] Iodine https://periodic.lanl.gov/53.shtml
Isotopes in Forensic Science and Anthropology
Information on the use of this element's isotopes in forensic science and anthropology.
131I (with a half-life of about 8 days) and 129I are both fission products; 129I is a long-lived fission product with a half-life of 1.7×107 years that can be helpful in the detection of the movement of radiation after a radioactive event, such as occurred at the Japanese reactors at Fukushima. In nuclear reactors and weapons tests, uranium and plutonium undergo fission processes in which one of the fission products is the long-lived isotope 129I. This isotope has been used as a groundwater tracer to determine evidence of nuclear fission, and it can also be tracked in rainwater as evidence of a fission event in the air (weapons explosion; Fig. IUPAC.53.1) [390] D. Elmore, H. E. Gove, R. Ferraro, L. R. Kilius, H. W. Lee, K. H. Chang, R. P. Beukens, A. E. Litherland, C. J. Russo, K. H. Purser, M. T. Murrell, R. C. Finkel. Nature286, 138 (1980)., [391] G. Snyder, U. Fehn. Nucl. Instrum. Methods Phys. Res. B223, 579 (2004)., [392] G. Snyder, A. Aldahan, G. Possnert. Geochem. Geophys.11, Q04010 (2010)..
Riferimenti (4)
- [390] D. Elmore, H. E. Gove, R. Ferraro, L. R. Kilius, H. W. Lee, K. H. Chang, R. P. Beukens, A. E. Litherland, C. J. Russo, K. H. Purser, M. T. Murrell, R. C. Finkel. Nature286, 138 (1980).
- [391] G. Snyder, U. Fehn. Nucl. Instrum. Methods Phys. Res. B223, 579 (2004).
- [392] G. Snyder, A. Aldahan, G. Possnert. Geochem. Geophys.11, Q04010 (2010).
- [4] IUPAC Periodic Table of the Elements and Isotopes (IPTEI) https://doi.org/10.1515/pac-2015-0703
Riferimenti
(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 Iodine.
The element property data was retrieved from publications.