Praseodymium (Pr)
lanthanideSolid
मानक परमाणु भार
140.90766 uइलेक्ट्रॉन विन्यास
[Xe] 6s2 4f3गलनांक
930.85 °Cक्वथनांक
3519.85 °Cघनत्व
6770 kg/m³ऑक्सीकरण अवस्थाएँ
0, +1, +2, +3, +4, +5विद्युतऋणात्मकता (पॉलिंग)
1.13आयनन ऊर्जा (प्रथम)
5.4702 eVखोज का वर्ष
1885परमाणु त्रिज्या
185 pmविवरण
Praseodymium is a light lanthanide and one of the rare-earth elements. In nature it occurs with other lanthanides, chiefly in minerals such as monazite and bastnäsite, and only in the +3 oxidation state under normal geochemical conditions. Its chemistry is dominated by Pr³⁺ salts and oxides, but the element is more readily oxidized to Pr⁴⁺ than most neighboring lanthanides. Praseodymium is technologically important in permanent magnets, optical materials, ceramics, and specialized alloys.
Praseodymium is soft, silvery, malleable, and ductile. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that falls off when exposed to air. As with other rare-earth metals, it should be kept under a light mineral oil or sealed in plastic.
The name derives from the Greek prasios for "green" and didymos for "twin" because of the pale green salts it forms. Praseodymium was discovered by the Austrian chemist Carl Auer (Baron von Welsbach) in 1885, who separated it and the element neodymium from a didymium sample (didymium had previously been thought to be a separate element).
Praseodymium was discovered by Carl F. Auer von Welsbach, an Austrian chemist, in 1885. He separated praseodymium, as well as the element neodymium, from a material known as didymium. Today, praseodymium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements.
From the Greek word prasios, green, and didymos, twin. In 1841 Mosander extracted the rare earth didymia from lanthana; in 1879, Lecoq de Boisbaudran isolated a new earth, samaria, from didymia obtained from the mineral samarskite. Six years later, in 1885, von Welsbach separated didymia into two others, praseodymia and neodymia, which gave salts of different colors. As with other rare earths, compounds of these elements in solution have distinctive sharp spectral absorption bands or lines, some of which are only a few Angstroms wide.
Pure praseodymium is a soft, silvery metal with a pale yellow cast when freshly cut. It tarnishes readily in air, forming oxide layers that can spall, so metal is usually stored under mineral oil, inert gas, or vacuum. It is malleable and reacts slowly with water, faster with dilute acids.
The largest use of praseodymium is in neodymium-iron-boron magnet alloys, where it can partly replace neodymium and help adjust magnetic and processing properties. Praseodymium compounds color glasses and ceramic glazes yellow to green, and mixed praseodymium-neodymium glass is used in didymium filters for glassworking eye protection. Praseodymium is also used in some mischmetal alloys, polishing and catalytic materials, and doped optical crystals or fibers for specialized lasers and signal devices.
Praseodymium's primary use is as an alloying agent with magnesium to create high-strength metals that are used in aircraft engines. Praseodymium also makes up about 5% of Misch metal, a material that is used to make flints for lighters. Praseodymium forms the core of carbon arc lights which are used in the motion picture industry for studio lighting and projector lights. Praseodymium is added to fiber optic cables as a doping agent where it is used as a signal amplifier. Praseodymium salts are used to give glasses and enamels a yellow color. Praseodymium is also a component of didymium glass, which is used to make certain types of welder's and glass blower's goggles.
Misch metal, used in making cigarette lighters, contains about 5% praseodymium metal. The rare-earth oxides, including Pr2O3 are among the most refractory substances known. Along with other rare earths, it is widely used as a core material for carbon arcs used by the motion picture industry for studio lighting and projection. Salts of praseodymium are used to color glasses and enamels; when mixed with certain other materials, praseodymium produces an intense and unusually clean yellow color in glass. Didymium glass, of which praseodymium is a component, is a colorant for welders goggles.
Isotopes in Medicine
Because of its relatively short half-life (19.12 h) and decay primarily by beta decay (96.3 percent beta decay and 3.7 percent alpha decay), 142Pr has been proposed for two main innovative applications in medicine, namely in microsphere brachytherapy and in eye plaque brachytherapy [425] M. C. Ferreira. Dosimetric Study of Beta-Minus Emitter Praseodymium-142: Applications in Microsphere Brachytherapy for Hepatocellular Carcinoma and Brachytherapy for Ocular Squamous Cell Carcinoma, East Carolina University Greenville, North Carolina, USA (2013).. 142Pr is advantageous because penetration of the beta fraction of the radiation is limited to a few millimeters in tissue, therefore limiting the dose of radiation to the treated site. 142Pr may be produced either by fast neutron activation or thermal neutron activation of stable 141Pr.
Research in metal-bearing radiopharmaceuticals is being conducted to determine the most efficient way to produce and process radioactive metals for in vivo tracing. This research has led to the development of a potential radionuclide generator that administers radioactive metal complexes to be observed during positron emission tomography (PET) imaging. A n(140Nd)/n(140Pr) amount-ratio radionuclide generator has been designed to administer 140Pr complexes, such as 140Pr-DTPA, to be used as a tracer during a PET scan [426] K. P. Zhernosekov. Radiochemical Aspects of Production and Processing of Radiometals for Preparation of Metalloradiopharmaceuticals, Johannes Gutenberg-Universität Mainz: Department of Chemistry, Pharmacy and Earth Sciences (2017), Feb. 27; https://publications.ub.uni-mainz.de/theses/volltexte/2006/1043/pdf/1043.pdf.. The half-life of 140Pr is 3.4 min. The n(140Nd)/n(140Pr) ratio radionuclide generators can also be used for administering 140Pr-phosphonate complexes to identify the development of skeletal metastases. Once the skeletal metastases are found, 153Sm-EDTMP can be administered as a radiotherapeutic agent to treat bone cancer (Fig. IUPAC.59.1) [426] K. P. Zhernosekov. Radiochemical Aspects of Production and Processing of Radiometals for Preparation of Metalloradiopharmaceuticals, Johannes Gutenberg-Universität Mainz: Department of Chemistry, Pharmacy and Earth Sciences (2017), Feb. 27; https://publications.ub.uni-mainz.de/theses/volltexte/2006/1043/pdf/1043.pdf.. The half-life of 153Sm is 1.9 days.
Praseodymium forms mainly trivalent compounds containing Pr³⁺, including praseodymium(III) chloride, PrCl₃, praseodymium(III) fluoride, PrF₃, and praseodymium(III) oxide, Pr₂O₃. Mixed-valence and tetravalent oxide chemistry is important: praseodymium(IV) oxide, PrO₂, and the nonstoichiometric oxide often written Pr₆O₁₁ are useful oxidizing and ceramic materials. Praseodymium salts are commonly green, and their optical absorption bands are sharp because 4f electrons are partly shielded from the ligand environment.
See more information at the Praseodymium compound page.
Praseodymium metal dust and filings can burn, and freshly divided material should be treated as a fire risk. Soluble praseodymium salts have low to moderate acute toxicity compared with many heavy metals, but they are not nutrients and should not be inhaled or ingested. Industrial hazards mainly involve dust exposure, reactive metal handling, hot processing, and co-exposure to acids, fluorides, or other chemicals used in separation and alloy production.
Praseodymium is dispersed in the crust with other light rare-earth elements and is concentrated by geological processes in phosphate and carbonate minerals. It is generally immobile in neutral soils and waters because Pr³⁺ strongly adsorbs to clays, oxides, and organic matter or precipitates with phosphate and carbonate. Mining and processing can release rare-earth-bearing dusts and tailings, but praseodymium is not known to have a specific biological role.
Praseodymium is produced as part of rare-earth mining and separation rather than from ores mined solely for Pr. Bastnäsite, monazite, and related concentrates are chemically cracked, and solvent extraction or ion-exchange methods separate the closely similar lanthanides. Demand is strongly linked to high-performance permanent magnets, where praseodymium and neodymium are often managed together as a didymium-rich stream. Supply is constrained by rare-earth separation capacity, environmental controls, and the need to balance production of many co-occurring lanthanides. Recycling from magnets and manufacturing scrap is technically possible and increasingly important, but separation from complex products remains difficult.
The element occurs along with other rare-earth elements in a variety of minerals. Monazite and bastnasite are the two principal commercial sources of the rare-earth metals. It was prepared in relatively pure form in 1931.
Praseodymium is much less abundant in the cosmos than iron-group elements but is a normal product of neutron-capture nucleosynthesis. Its stable isotope, ¹⁴¹Pr, is formed through s-process and r-process pathways in evolved stars and explosive events. In planetary materials it follows other refractory lithophile rare-earth elements and is enriched in differentiated crustal rocks relative to primitive mantle materials.
- Natural praseodymium is essentially monoisotopic, consisting of stable ¹⁴¹Pr.
- The name comes from Greek words meaning “green twin,” referring to the color of its salts and its separation from didymr
- Pr₆O₁₁ is often called praseodymium oxide, although it is not a simple single-valence oxide.
- Praseodymium can replace part of neodymium in many commercial magnet compositions.
- Pr³⁺ absorption lines can give praseodymium glass a distinctive yellow-green filter behavior.
चित्र
गुण
भौतिक
- परमाणु त्रिज्या (आनुभविक)
- 185 pm सभी तत्वों की परमाणु त्रिज्या (आनुभविक) की तुलना करें →
- सहसंयोजक त्रिज्या
- 203 pm सभी तत्वों की सहसंयोजक त्रिज्या की तुलना करें →
- वान डर वाल्स त्रिज्या
- 239 pm सभी तत्वों की वान डर वाल्स त्रिज्या की तुलना करें →
- घनत्व
- 6770 kg/m³ सभी तत्वों की घनत्व की तुलना करें →
- मोलर आयतन
- 0.0208 L/mol
- STP पर प्रावस्था
- ठोस सभी तत्वों की STP पर प्रावस्था की तुलना करें →
- गलनांक
- 930.85 °C सभी तत्वों की गलनांक की तुलना करें →
- क्वथनांक
- 3519.85 °C सभी तत्वों की क्वथनांक की तुलना करें →
- तापीय चालकता
- 12.5 W/(m·K) सभी तत्वों की तापीय चालकता की तुलना करें →
- विशिष्ट ऊष्मा धारिता
- 0.193 J/(g·K) सभी तत्वों की विशिष्ट ऊष्मा धारिता की तुलना करें →
- मोलर ऊष्मा धारिता
- 27.2 J/(mol·K) सभी तत्वों की मोलर ऊष्मा धारिता की तुलना करें →
- क्रिस्टल संरचना
- षट्कोणीय सघन संकुलित सभी तत्वों की क्रिस्टल संरचना की तुलना करें →
रासायनिक
- विद्युतऋणात्मकता (पॉलिंग)
- 1.13 सभी तत्वों की विद्युतऋणात्मकता (पॉलिंग) की तुलना करें →
- इलेक्ट्रॉन बंधुता
- 0.962 eV
- आयनन ऊर्जा (प्रथम)
- 5.4702 eV सभी तत्वों की आयनन ऊर्जा (प्रथम) की तुलना करें →
- आयनन ऊर्जा (द्वितीय)
- 10.631037 eV सभी तत्वों की आयनन ऊर्जा (द्वितीय) की तुलना करें →
- आयनन ऊर्जा (तृतीय)
- 21.623774 eV सभी तत्वों की आयनन ऊर्जा (तृतीय) की तुलना करें →
- आयनन ऊर्जा (चतुर्थ)
- 38.981134 eV सभी तत्वों की आयनन ऊर्जा (चतुर्थ) की तुलना करें →
- आयनन ऊर्जा (पंचम)
- 57.530198 eV सभी तत्वों की आयनन ऊर्जा (पंचम) की तुलना करें →
- ऑक्सीकरण अवस्थाएँ
- 0, +1, +2, +3, +4, +5 सभी तत्वों की ऑक्सीकरण अवस्थाएँ की तुलना करें →
- संयोजकता इलेक्ट्रॉन
- 3 सभी तत्वों की संयोजकता इलेक्ट्रॉन की तुलना करें →
- इलेक्ट्रॉन विन्यास
- [Xe] 6s2 4f3
ऊष्मागतिक
- गलन ऊष्मा
- 0.07141006 eV सभी तत्वों की गलन ऊष्मा की तुलना करें →
- वाष्पन ऊष्मा
- 3.078199 eV सभी तत्वों की वाष्पन ऊष्मा की तुलना करें →
- ऊर्ध्वपातन ऊष्मा
- 3.430585 eV
- परमाणुकरण ऊष्मा
- 3.430585 eV
- परमाणुकरण एन्थैल्पी
- 3.699021 eV
नाभिकीय
- प्रोटॉन
- 59 सभी तत्वों की प्रोटॉन की तुलना करें →
- न्यूट्रॉन
- 82 सभी तत्वों की न्यूट्रॉन की तुलना करें →
- ज्ञात समस्थानिक
- 41 सभी तत्वों की ज्ञात समस्थानिक की तुलना करें →
- स्थिर समस्थानिक
- 1 सभी तत्वों की स्थिर समस्थानिक की तुलना करें →
- सबसे स्थिर समस्थानिक
- Pr-141
- खोज का वर्ष
- 1885
प्रचुरता
- प्रचुरता (भूपर्पटी)
- 9.2 mg/kg सभी तत्वों की प्रचुरता (भूपर्पटी) की तुलना करें →
- प्रचुरता (महासागर)
- 6.4 × 10−7 mg/L सभी तत्वों की प्रचुरता (महासागर) की तुलना करें →
क्रिस्टल संरचना
- जालक स्थिरांक a
- 367 pm
इलेक्ट्रॉनिक संरचना
- प्रति कोश इलेक्ट्रॉन
- 2, 8, 18, 21, 8, 2 सभी तत्वों की प्रति कोश इलेक्ट्रॉन की तुलना करें →
पहचानकर्ता
- CAS संख्या
- 7440-10-0 सभी तत्वों की CAS संख्या की तुलना करें →
- टर्म प्रतीक
- 4I°9/2
- InChI
- InChI=1S/Pr
- InChI कुंजी
- PUDIUYLPXJFUGB-UHFFFAOYSA-N
इलेक्ट्रॉन विन्यास मापित
Pr: 4f³ 6s²[Xe] 4f³ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f³ 6s²परमाणु 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
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु |
|---|---|---|---|
| 141 स्थिर | 140.9076576 ± 0.0000023 | 100.0000% | स्थिर |
प्रावस्था / अवस्था
कारण: गलनांक (930.85 °C) से 905.9 °C कम
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
ऊर्ध्वपातनांक पर 1 mol के ऊर्ध्वपातन के लिए आवश्यक ऊर्जा
घनत्व
मानक परिस्थितियों में
मानक परिस्थितियों में
परमाणु स्पेक्ट्रम
59 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 |
|---|---|---|---|---|
| Pr I | 0 | 182 | 0 | 0 |
| Pr II | +1 | 548 | 172 | 356 |
| Pr III | +2 | 372 | 0 | 0 |
| Pr IV | +3 | 135 | 0 | 0 |
| Pr V | +4 | 12 | 0 | 0 |
उपलब्ध ऊर्जा स्तर डेटा ?
| आयन | आवेश | स्तर |
|---|---|---|
| Pr I | 0 | 430 |
| Pr II | +1 | 201 |
| Pr III | +2 | 430 |
| Pr IV | +3 | 104 |
| Pr V | +4 | 9 |
| Pr VI | +5 | 2 |
| Pr VII | +6 | 2 |
| Pr VIII | +7 | 2 |
| Pr IX | +8 | 2 |
| Pr X | +9 | 2 |
आयनिक त्रिज्याएँ
| आवेश | उपसहसंयोजन | प्रचक्रण | त्रिज्या |
|---|---|---|---|
| +3 | 6 | उपलब्ध नहीं | 99 pm |
| +3 | 8 | उपलब्ध नहीं | 112.6 pm |
| +3 | 9 | उपलब्ध नहीं | 117.9 pm |
| +4 | 6 | उपलब्ध नहीं | 85 pm |
| +4 | 8 | उपलब्ध नहीं | 96 pm |
यौगिक
समस्थानिक (1)
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु | क्षय का प्रकार | |
|---|---|---|---|---|---|
| 141 स्थिर | 140.9076576 ± 0.0000023 | 100.0000% | स्थिर | stable |
विस्तृत गुण
सहसंयोजक त्रिज्याएँ (विस्तृत)
- सहसंयोजक त्रिज्या (प्यूक्को)
- 176 pm
- सहसंयोजक त्रिज्या (प्यूक्को, द्विबंध)
- 138 pm
- सहसंयोजक त्रिज्या (प्यूक्को, त्रिबंध)
- 128 pm
वान डर वाल्स त्रिज्याएँ
- Alvarez
- 292 pm
- UFF
- 360.6 pm
- MM3
- 273 pm
परमाणु और धात्विक त्रिज्याएँ
- परमाणु त्रिज्या (राह्म)
- 286 pm
संख्यांकन मापक्रम
- Mendeleev
- 17
- Pettifor
- 31
- Glawe
- 30
विद्युतऋणात्मकता मापक्रम
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 4
ध्रुवणीयता और परिक्षेपण
- द्विध्रुव ध्रुवणीयता
- 216 a.u.
- द्विध्रुव ध्रुवणीयता (अनिश्चितता)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3760 Ha·Bohr6
मीडेमा प्राचल
- मीडेमा मोलर आयतन
- 20.79 cm3/mol
- मीडेमा इलेक्ट्रॉन घनत्व
- 2
आपूर्ति जोखिम और अर्थशास्त्र
- उत्पादन संकेंद्रण
- 97
- सापेक्ष आपूर्ति जोखिम
- 10
- भंडार वितरण
- 50
- राजनीतिक स्थिरता (प्रमुख उत्पादक)
- 24
- राजनीतिक स्थिरता (सबसे अधिक भंडार वाला देश)
- 24
प्रावस्था संक्रमण और अपररूप
| गलनांक | 1204.15 K |
| क्वथनांक | 3793.15 K |
ऑक्सीकरण अवस्था की श्रेणियाँ
उन्नत संदर्भ डेटा
परिरक्षण स्थिरांक (13)
| n | कक्षक | σ |
|---|---|---|
| 1 | s | 1.1694 |
| 2 | p | 4.2306 |
| 2 | s | 15.538 |
| 3 | d | 13.8476 |
| 3 | p | 19.1756 |
| 3 | s | 19.499 |
| 4 | d | 32.7028 |
| 4 | f | 37.8992 |
| 4 | p | 29.9432 |
| 4 | s | 28.6668 |
क्रिस्टल त्रिज्याओं का विवरण (5)
| आवेश | CN | प्रचक्रण | rcrystal (pm) | उत्पत्ति |
|---|---|---|---|---|
| 3 | VI | 113 | from r^3 vs V plots, | |
| 3 | VIII | 126.6 | from r^3 vs V plots, | |
| 3 | IX | 131.9 | from r^3 vs V plots, | |
| 4 | VI | 99 | from r^3 vs V plots, | |
| 4 | VIII | 110 | from r^3 vs V plots, |
समस्थानिक क्षय के प्रकार (58)
| समस्थानिक | मोड | तीव्रता |
|---|---|---|
| 121 | p | 100% |
| 122 | B+ | — |
| 122 | B+p | — |
| 123 | B+ | — |
| 123 | B+p | — |
| 124 | B+ | 100% |
| 124 | B+p | — |
| 125 | B+ | 100% |
| 125 | B+p | — |
| 126 | B+ | 100% |
एक्स-रे प्रकीर्णन गुणक (508)
| ऊर्जा (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 1.26325 |
| 10.1617 | — | 1.25455 |
| 10.3261 | — | 1.24591 |
| 10.4931 | — | 1.23732 |
| 10.6628 | — | 1.22879 |
| 10.8353 | — | 1.22033 |
| 11.0106 | — | 1.21192 |
| 11.1886 | — | 1.20357 |
| 11.3696 | — | 1.19528 |
| 11.5535 | — | 1.18704 |
अतिरिक्त डेटा
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
9.2 milligrams per kilogram
संदर्भ (1)
- [5] Praseodymium https://education.jlab.org/itselemental/ele059.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
6.4×10-7 milligrams per liter
संदर्भ (1)
- [5] Praseodymium https://education.jlab.org/itselemental/ele059.html
Sources
Sources of this element.
The element occurs along with other rare-earth elements in a variety of minerals. Monazite and bastnasite are the two principal commercial sources of the rare-earth metals. It was prepared in relatively pure form in 1931.
संदर्भ (1)
- [6] Praseodymium https://periodic.lanl.gov/59.shtml
Production
Production of this element (from raw materials or other compounds containing the element).
Ion-exchange and solvent extraction techniques have led to much easier isolation of the rare earths and the cost has dropped greatly in the past few years. Praseodymium can be prepared by several methods, such as by calcium reduction of the anhydrous chloride of fluoride.
संदर्भ (1)
- [6] Praseodymium https://periodic.lanl.gov/59.shtml
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 Praseodymium.
The element property data was retrieved from publications.