Chemicool

Pr

59

140.9077
Praseodymium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
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

States
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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Energies
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

Reactions
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

Radius
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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Conductivity
thermal conductivity 12.5 J/m-sec-deg electrical conductivity 14.706 1/mohm-cm
polarizability 28.2 A^3

Abundance
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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