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Protactinium
Chemical Properties & Compounds
| Symbol | Atomic Number | Atomic Weight | Melting Point | Boiling Point | Phase | Density | Classification |
| Pa | 91 | 231.03588 | 1568 °C | 4027 °C | Solid | 15.37 g/cm3 | Metal  |
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| General |
| Name, Symbol, Number |
protactinium, Pa, 91 |
| Chemical series |
actinides |
| Group, Period, Block |
n/a, 7, f |
| Appearance |
bright, silvery metallic luster |
| Standard atomic weight |
231.03588(2) g·mol−1 |
| Electron configuration |
[Rn] 5f2 6d1 7s2 |
| Electrons per shell |
2, 8, 18, 32, 20, 9, 2 |
| Physical properties |
| Phase |
solid |
| Density (near r.t.) |
15.37 g·cm−3 |
| Melting point |
1841 K
(1568 °C, 2854 °F) |
| Boiling point |
? 4300 K
(? 4027 °C, ? °F) |
| Heat of fusion |
12.34 kJ·mol−1 |
| Heat of vaporization |
481 kJ·mol−1 |
| Atomic properties |
| Crystal structure |
orthorhombic |
| Oxidation states |
2, 3, 4, 5
(weakly basic oxide) |
| Electronegativity |
1.5 (scale Pauling) |
| Ionization energies |
1st: 568 kJ/mol |
| Atomic radius |
180 pm |
| Miscellaneous |
| Magnetic ordering |
no data |
| Electrical resistivity |
(0 °C) 177 nΩ·m |
| Thermal conductivity |
(300 K) 47 W·m−1·K−1 |
| CAS registry number |
7440-13-3 |
| Selected isotopes |
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| References |
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Protactinium Compounds
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Source: Wikipedia article Protactinium
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Chemistry Quick Facts