General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Praseodymium Symbol Pr
atomic number 59 Atomic weight 140.9077
Density @ 293 K 6.77 g/cm3 Atomic volume 20.8 cm3/mol
Group Rare Earth, Lanthanides discovered 1885


state (s, l, g) s
melting point 1204.2 K boiling point 3293 K
Heat of fusion 6.890 kJ/mol Heat of vaporization 296.80 kJ/mol
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1st ionization energy 523.2 kJ/mole electronegativity 1.13
2nd ionization energy 1018 kJ/mole electron affinity 50 kJ/mole
3rd ionization energy 2086 kJ/mole Specific heat 0.19 J/gK
heat atomization 356 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,21,8,2 electron configuration [Xe] 4f3 6s2
minimum oxidation number 0 maximum oxidation number 4
min. common oxidation no. 0 max. common oxidation no. 3
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Appearance & Characteristics

structure cp: close packed (ABCB) color silvery-white
uses alloys, Welder's mask toxicity
hardness mohs characteristics soft


reaction with air vigorous, = Pr6O11 approx reaction with 6M HCl mild, = H2, PrCl3
reaction with 6M HCl mild, = H2, PrCl3 reaction with 15M HNO3 mild, = Pr(NO3)3
reaction with 6M NaOH
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Other Forms

number of isotopes 1 hydride(s) PrH2 PrH3
oxide(s) PrO2 Pr6O11 chloride(s) PrCl3


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 182 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 113 pm
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thermal conductivity 12.5 J/m-sec-deg electrical conductivity 14.706 1/mohm-cm
polarizability 28.2 A^3


source Monazite(phosphate),bastnaesite rel. abund. solar system -0.778 log
abundance earth's crust 0.9 log cost, pure 170 $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.