General: |
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Name: Protactinium
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Symbol: Pa
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Group: Rare Earth, Actinides
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Atomic weight: 231.0359
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Density @ 293 K: 15.4 g/cm3
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Atomic volume: 15.0 cm3/mol
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Group: Rare Earth, Actinides
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discovered: 1917
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States: |
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state (s, l, g): s
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melting point: 1873.2 K
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boiling point: 4500 K
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Heat of fusion: 12.30 kJ/mol
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Heat of vaporization: ?
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Energies: |
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1st ionization energy: 568 kJ/mole
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electronegativity: 1.5
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2nd ionization energy: kJ/mole
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electron affinity: kJ/mole
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3rd ionization energy: kJ/mole
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Specific heat: 0.12 J/gK
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heat atomization: 527 kJ/mole atoms
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Oxidation & Electrons: |
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Shells: 2,8,18,32,20,9,2
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electron configuration: [Rn] 5f2 6d1 7s2
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minimum oxidation number: 0
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maximum oxidation number: 5
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min. common oxidation no.: 0
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max. common oxidation no.: 5
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Appearance & Characteristics: |
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structure: fcc: face-centered cubic
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color: silvery
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uses:
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toxicity:
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hardness: mohs
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characteristics: Radioactive
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Reactions: |
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reaction with air:
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reaction with 6M HCl:
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reaction with 6M HCl:
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reaction with 15M HNO3:
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reaction with 6M NaOH: none
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Other Forms: |
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number of isotopes: 1
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hydride(s): PaH3
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oxide(s): PaO PaO2 Pa2O5
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chloride(s): PaCl4 PaCl5
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Radius: |
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ionic radius (2- ion): pm
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ionic radius (1- ion): pm
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atomic radius: 163 pm
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ionic radius (1+ ion): pm
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ionic radius (2+ ion): pm
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ionic radius (3+ ion): 118 pm
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Conductivity: |
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thermal conductivity: J/m-sec-deg
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electrical conductivity: 1/mohm-cm
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polarizability: 25.4 A^3
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Abundance: |
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source: Synthetic(U-235 decay)
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rel. abund. solar system: log
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abundance earth's crust: -5.9 log
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cost, pure: $/100g
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cost, bulk: $/100g
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