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59
Pr
140.9077
Praseodymium |
Appearance & Characteristics | Reactions |
Other Forms Radius | Conductivity | Abundance
General:
| Name: Praseodymium | Symbol: Pr |
| Group: Rare Earth, Lanthanides | 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): solid | |
| Melting point: 1204.2 K | Boiling point: 3293 K |
| Heat of fusion: 6.890 kJ/mol | Heat of vaporization: 296.80 kJ/mol |
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 |
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 6 M HCl: mild, => H2, PrCl3 | Reaction with 6 M HCl: mild, => H2, PrCl3 |
| Reaction with 15 M HNO3: mild, => Pr(NO3)3 | Reaction with 6 M NaOH: |
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 |
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 |
