Praseodymium (Pr)
lanthanideSolid
प्रमाणित अणुभार
140.90766 uइलेक्ट्रॉन संरूपण
[Xe] 6s2 4f3द्रवणांक
930.85 °Cउत्कलनांक
3519.85 °Cघनता
6770 kg/m³ऑक्सिडीकरण अवस्था
0, +1, +2, +3, +4, +5विद्युतऋणता (पॉलिंग)
1.13आयनीकरण ऊर्जा (पहिली)
5.4702 eVशोधाचे वर्ष
1885अणुत्रिज्या
185 pmतपशील
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.
प्रतिमा
गुणधर्म
भौतिक
- अणुत्रिज्या (अनुभवाधारित)
- 185 pm सर्व घटकांच्या अणुत्रिज्या (अनुभवाधारित) ची तुलना करा →
- सहसंयुजी त्रिज्या
- 203 pm सर्व घटकांच्या सहसंयुजी त्रिज्या ची तुलना करा →
- व्हॅन डर वाल्स त्रिज्या
- 239 pm सर्व घटकांच्या व्हॅन डर वाल्स त्रिज्या ची तुलना करा →
- घनता
- 6770 kg/m³ सर्व घटकांच्या घनता ची तुलना करा →
- मोलर आयतन
- 0.0208 L/mol
- STP येथे अवस्था
- घन सर्व घटकांच्या STP येथे अवस्था ची तुलना करा →
- द्रवणांक
- 930.85 °C सर्व घटकांच्या द्रवणांक ची तुलना करा →
- उत्कलनांक
- 3519.85 °C सर्व घटकांच्या उत्कलनांक ची तुलना करा →
- उष्णता चालकता
- 12.5 W/(m·K) सर्व घटकांच्या उष्णता चालकता ची तुलना करा →
- विशिष्ट उष्माधारकता
- 0.193 J/(g·K) सर्व घटकांच्या विशिष्ट उष्माधारकता ची तुलना करा →
- मोलर उष्माधारकता
- 27.2 J/(mol·K) सर्व घटकांच्या मोलर उष्माधारकता ची तुलना करा →
- स्फटिक संरचना
- षट्कोणी निकट-संकुलित सर्व घटकांच्या स्फटिक संरचना ची तुलना करा →
रासायनिक
- विद्युतऋणता (पॉलिंग)
- 1.13 सर्व घटकांच्या विद्युतऋणता (पॉलिंग) ची तुलना करा →
- इलेक्ट्रॉन आसक्ती
- 0.962 eV
- आयनीकरण ऊर्जा (पहिली)
- 5.4702 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पहिली) ची तुलना करा →
- आयनीकरण ऊर्जा (दुसरी)
- 10.631037 eV सर्व घटकांच्या आयनीकरण ऊर्जा (दुसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (तिसरी)
- 21.623774 eV सर्व घटकांच्या आयनीकरण ऊर्जा (तिसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (चौथी)
- 38.981134 eV सर्व घटकांच्या आयनीकरण ऊर्जा (चौथी) ची तुलना करा →
- आयनीकरण ऊर्जा (पाचवी)
- 57.530198 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पाचवी) ची तुलना करा →
- ऑक्सिडीकरण अवस्था
- 0, +1, +2, +3, +4, +5 सर्व घटकांच्या ऑक्सिडीकरण अवस्था ची तुलना करा →
- संयुजा इलेक्ट्रॉन
- 3 सर्व घटकांच्या संयुजा इलेक्ट्रॉन ची तुलना करा →
- इलेक्ट्रॉन संरूपण
- [Xe] 6s2 4f3
उष्मागतिक
- द्रवण उष्मा
- 0.07141006 eV सर्व घटकांच्या द्रवण उष्मा ची तुलना करा →
- बाष्पीभवन उष्मा
- 3.078199 eV सर्व घटकांच्या बाष्पीभवन उष्मा ची तुलना करा →
- संप्लवन उष्मा
- 3.430585 eV
- अणूकरण उष्मा
- 3.430585 eV
- अणूकरण एन्थाल्पी
- 3.699021 eV
केंद्रकीय
- प्रोटॉन
- 59 सर्व घटकांच्या प्रोटॉन ची तुलना करा →
- न्यूट्रॉन
- 82 सर्व घटकांच्या न्यूट्रॉन ची तुलना करा →
- ज्ञात समस्थानिके
- 41 सर्व घटकांच्या ज्ञात समस्थानिके ची तुलना करा →
- स्थिर समस्थानिके
- 1 सर्व घटकांच्या स्थिर समस्थानिके ची तुलना करा →
- सर्वाधिक स्थिर समस्थानिक
- Pr-141
- शोधाचे वर्ष
- 1885
विपुलता
- विपुलता (पृथ्वीचे कवच)
- 9.2 mg/kg सर्व घटकांच्या विपुलता (पृथ्वीचे कवच) ची तुलना करा →
- विपुलता (महासागर)
- 6.4 × 10−7 mg/L सर्व घटकांच्या विपुलता (महासागर) ची तुलना करा →
स्फटिक संरचना
- जालक स्थिरांक a
- 367 pm
इलेक्ट्रॉन संरचना
- प्रत्येक कवचातील इलेक्ट्रॉन
- 2, 8, 18, 21, 8, 2 सर्व घटकांच्या प्रत्येक कवचातील इलेक्ट्रॉन ची तुलना करा →
ओळखचिन्हे
- CAS क्रमांक
- 7440-10-0 सर्व घटकांच्या CAS क्रमांक ची तुलना करा →
- टर्म चिन्ह
- 4I°9/2
- InChI
- InChI=1S/Pr
- InChI की
- PUDIUYLPXJFUGB-UHFFFAOYSA-N
इलेक्ट्रॉन संरूपण मोजलेले
Pr: 4f³ 6s²[Xe] 4f³ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f³ 6s²अणुप्रतिमान
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
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य |
|---|---|---|---|
| 141 स्थिर | १४०.९०७६५७६ ± ०.०००००२३ | 100.0000% | स्थिर |
अवस्था / स्थिती
कारण: द्रवणांकापेक्षा (930.85 °C) 905.9 °C कमी
योजनात्मक, प्रमाणानुसार नाही
अवस्थांतर बिंदू
अवस्थांतर ऊर्जा
द्रवणांकावर 1 mol वितळवण्यासाठी आवश्यक ऊर्जा
उत्कलनांकावर 1 mol चे बाष्पीभवन करण्यासाठी आवश्यक ऊर्जा
संप्लवनांकावर 1 mol चे संप्लवन करण्यासाठी आवश्यक ऊर्जा
घनता
प्रमाणित परिस्थितीत
प्रमाणित परिस्थितीत
अणुवर्णपट
59 पैकी 10 दाखवले आहेत. आयनाच्या विद्युतभारानुसार चढत्या क्रमाने मांडलेले.
वर्णरेषांचा संग्रह ?
| आयन | विद्युतभार | एकूण वर्णरेषा | संक्रमण संभाव्यता | पातळ्यांची नामांकने |
|---|---|---|---|---|
| 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 |
ऊर्जा पातळ्यांचा संग्रह ?
| आयन | विद्युतभार | पातळ्या |
|---|---|---|
| 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 त्रिज्या
| विद्युतभार | समन्वय | प्रचक्रण | त्रिज्या |
|---|---|---|---|
| +3 | 6 | उपलब्ध नाही | 99 pm |
| +3 | 8 | उपलब्ध नाही | 112.6 pm |
| +3 | 9 | उपलब्ध नाही | 117.9 pm |
| +4 | 6 | उपलब्ध नाही | 85 pm |
| +4 | 8 | उपलब्ध नाही | 96 pm |
संयुगे
समस्थानिके (1)
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य | क्षय प्रकार | |
|---|---|---|---|---|---|
| 141 स्थिर | १४०.९०७६५७६ ± ०.०००००२३ | 100.0000% | स्थिर | stable |
विस्तारित गुणधर्म
सहसंयुजी त्रिज्या (विस्तारित)
- सहसंयुजी त्रिज्या (प्युक्को)
- 176 pm
- सहसंयुजी त्रिज्या (प्युक्को, दुहेरी बंध)
- 138 pm
- सहसंयुजी त्रिज्या (प्युक्को, तिहेरी बंध)
- 128 pm
व्हॅन डर वाल्स त्रिज्या
- Alvarez
- 292 pm
- UFF
- 360.6 pm
- MM3
- 273 pm
अणुत्रिज्या आणि धात्विक त्रिज्या
- अणुत्रिज्या (राह्म)
- 286 pm
क्रमांकन मापनपट्ट्या
- Mendeleev
- 17
- Pettifor
- 31
- Glawe
- 30
विद्युतऋणता मापनपट्ट्या
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 4
ध्रुवणक्षमता आणि अपस्करण
- द्विध्रुव ध्रुवणक्षमता
- 216 a.u.
- द्विध्रुव ध्रुवणक्षमता (अनिश्चितता)
- 20 a.u.
- C₆ (Gould–Bučko)
- 3760 Ha·Bohr6
मिडेमा प्राचल
- मिडेमा मोलर आयतन
- 20.79 cm3/mol
- मिडेमा इलेक्ट्रॉन घनता
- 2
पुरवठा जोखीम आणि अर्थकारण
- उत्पादनाचे केंद्रीकरण
- 97
- सापेक्ष पुरवठा जोखीम
- 10
- साठ्यांचे वितरण
- 50
- राजकीय स्थैर्य (प्रमुख उत्पादक)
- 24
- राजकीय स्थैर्य (सर्वाधिक साठे असलेला देश)
- 24
अवस्थांतरे आणि अपरूपे
| द्रवणांक | 1204.15 K |
| उत्कलनांक | 3793.15 K |
ऑक्सिडीकरण अवस्थांचे वर्ग
प्रगत संदर्भ माहिती
परिरक्षण स्थिरांक (13)
| n | कक्षिका | 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 |
स्फटिक त्रिज्यांचा तपशील (5)
| विद्युतभार | CN | प्रचक्रण | rcrystal (pm) | उत्पत्ती |
|---|---|---|---|---|
| 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 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% |
क्ष-किरण 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 माहिती
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.