Periodic Table/Praseodymium
← CeNd →
59Pr140.9077 Da

Praseodymium

Lanthanide·Period 6·f-block

Soft silvery metallic element, belongs to the lanthanoids. Only natural isotope is Pr-141 which is not radioactive. Fourteen radioactive isotopes have been artificially produced. Used in rare-earth alloys. Discovered in 1885 by C.A. von Welsbach.

Gallery

1.5 Grams Praseodymium under Argon, 0.5 cm big pieces

Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/praseodymium.php

Bohr model of Praseodymium

Physical Propertiesmass · density · phase · crystal

Atomic Mass

140.9077Da

Density

6.7730g/cm³

Phase (STP)

Solid

Melting Point

1204.2K

Boiling Point

3793.2K

Molar Heat

0.1930J/(mol·K)

Crystal Structure

HEX

Lattice Constant

3.670Å

Atomic Radiiatomic · covalent · van der Waals

Atomic (Empirical)

185.00pm

Covalent

176.00pm

Van der Waals

240.00pm

Electronic Propertieselectronegativity · ionization · affinity

Electron Configuration

[Xe] 4f3 6s2

Electron Shells

2, 8, 18, 21, 8, 2

Electronegativity

1.13Pauling

Electron Affinity

1.0kJ/mol

1st Ionization Energy

5.5kJ/mol

Oxidation States

+2, +3, +4

Orbital DiagramAufbau · Hund's rule · Pauli exclusion

↑↓
1s2
↑↓
2s2
↑↓
↑↓
↑↓
2p6
↑↓
3s2
↑↓
↑↓
↑↓
3p6
↑↓
↑↓
↑↓
↑↓
↑↓
3d10
↑↓
4s2
↑↓
↑↓
↑↓
4p6
↑↓
↑↓
↑↓
↑↓
↑↓
4d10
↑↓
5s2
↑↓
↑↓
↑↓
5p6
↑
↑
↑
4f3
↑↓
6s2

Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f3 6s2Short: [Xe] 4f3 6s2

Ionization Energies (59 known)

1st5.5 kJ/mol2nd10.6 kJ/mol3rd21.6 kJ/mol4th39.0 kJ/mol5th57.5 kJ/mol6th82.0 kJ/mol7th97.0 kJ/mol8th112.0 kJ/mol9th131.0 kJ/mol10th148.0 kJ/mol11th162.0 kJ/mol12th196.0 kJ/mol13th217.0 kJ/mol14th350.0 kJ/mol15th378.0 kJ/mol16th412.0 kJ/mol17th445.0 kJ/mol18th478.0 kJ/mol19th516.0 kJ/mol20th554.0 kJ/mol21th590.0 kJ/mol22th627.0 kJ/mol23th663.0 kJ/mol24th803.0 kJ/mol25th840.0 kJ/mol26th880.0 kJ/mol27th920.0 kJ/mol28th985.0 kJ/mol29th1028.0 kJ/mol30th1124.0 kJ/mol31th1169.9 kJ/mol32th2019.0 kJ/mol33th2108.0 kJ/mol34th2202.0 kJ/mol35th2304.0 kJ/mol36th2400.0 kJ/mol37th2501.0 kJ/mol38th2628.0 kJ/mol39th2729.0 kJ/mol40th2838.0 kJ/mol41th2941.0 kJ/mol42th3227.0 kJ/mol43th3319.0 kJ/mol44th3419.0 kJ/mol45th3512.0 kJ/mol46th3729.0 kJ/mol47th3832.0 kJ/mol48th4030.0 kJ/mol49th4130.0 kJ/mol50th9378.0 kJ/mol51th9632.0 kJ/mol52th9913.0 kJ/mol53th10175.0 kJ/mol54th10959.0 kJ/mol55th11262.0 kJ/mol56th11641.0 kJ/mol57th11895.9 kJ/mol58th48571.7 kJ/mol59th49722.4 kJ/molSuccessive Ionization Energies

Emission Spectrumvisible range · characteristic spectral lines

495
496
513
Pr emission
380nm750nm
495.1 nm(100%)496.3 nm(70%)513.3 nm(40%)

Abundanceby mass

🌍Earth's Crust
9.2 ppm
🌊Ocean
6.0e-7 ppm
✨Universe
200.0 ppt
🧬Human Body—

Log scale · ppm = parts per million by mass

Biological Role

No biological role

No known biological role.

Discovery

Discovered By

C.F. Aver von Welsbach

Named By

—

Year

1885

Nuclear Data

Known Isotopes

41

Stable Isotopes

1

Stable Mass Numbers

141

Natural isotopic abundance (IUPAC recommended values)

Isotopes of Pr41 known

NuclideZNMass (AMU)Half-lifeDecayJπAbundance
121Pr5962120.95539312.0 msp (1%)3/2—
122Pr5963121.951927Unknownβ⁺, β⁺p——
123Pr5964122.946076Unknownβ⁺, β⁺p3/2+—
141Prstable5982140.907660Stablestable (1%)5/2+10000.0000%
159Pr59100158.956232134 msβ⁻ (1%), β⁻n3/2-—
160Pr59101159.961138170 msβ⁻ (1%), β⁻n1+—
161Pr59102160.965121Unknownβ⁻, β⁻n3/2-—

Click any isotope for its full page with decay chain:

121Pr122Pr123Pr124Pr125Pr126Pr127Pr128Pr129Pr130Pr131Pr132Pr133Pr134Pr135Pr136Pr137Pr138Pr139Pr140Pr141Pr142Pr143Pr144Pr145Pr146Pr147Pr148Pr149Pr150Pr151Pr152Pr153Pr154Pr155Pr156Pr157Pr158Pr159Pr160Pr161Pr
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