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RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe
CsBaLaCePrNdPmSmEuGdTbDyHoErTmYbLuHfTaWReOsIrPtAuHgTlPbBiPoAtRn
FrRaAcThPaUNpPuAmCmBkCfEsFmMdNoLrRfDbSgBhHsMtDsRgCnNhFlMcLvTsOg

Technical data for Protactinium

Click any property name to see plots of that property for all the elements.

Overview
NameProtactinium
SymbolPa
Atomic Number91
Atomic Weight231.03588[note]
Density15.37 g/cm3
Melting Point1572 °C
Boiling Point4000 °C

Thermal properties
PhaseSolid
Melting Point1572 °C
Boiling Point4000 °C
Absolute Melting Point1845 K
Absolute Boiling Point4273 K
Critical PressureN/A
Critical TemperatureN/A
Heat of Fusion15 kJ/mol
Heat of Vaporization470 kJ/mol
Specific Heat99.1 J/(kg K)[note]
Adiabatic IndexN/A
Neel PointN/A
Thermal Conductivity47 W/(m K)
Thermal ExpansionN/A

Bulk physical properties
Density15.37 g/cm3
Density (Liquid)N/A
Molar Volume0.0000150316
Brinell HardnessN/A
Mohs HardnessN/A
Vickers HardnessN/A
Bulk ModulusN/A
Shear ModulusN/A
Young ModulusN/A
Poisson RatioN/A
Refractive IndexN/A
Speed of SoundN/A
Thermal Conductivity47 W/(m K)
Thermal ExpansionN/A

Reactivity
Valence5
Electronegativity1.5
ElectronAffinityN/A
Ionization Energies
568 kJ/mol

Health and Safety
DOT Hazard ClassN/A
DOT NumbersN/A
RTECS NumberN/A
NFPA LabelN/A

Classifications
Alternate NamesNone
Names of AllotropesNone
Blockf
GroupN/A
Period7
SeriesActinide
Electron Configuration[Rn]7s25f26d1
ColorSilver
Discovery
1913 in Germany and The United Kingdom
Gas phaseN/A
CAS NumberCAS7440-13-3
CID NumberN/A
RTECS NumberN/A

Electrical properties
Electrical TypeConductor
Electrical Conductivity5.6×106 S/m
Resistivity1.8×10-7 m Ω
Superconducting Point1.41

Magnetic properties
Magnetic TypeParamagnetic
Curie PointN/A
Mass Magnetic Susceptibility3.25×10-8 m3/Kg
Molar Magnetic Susceptibility7.509×10-9 m3/mol
Volume Magnetic Susceptibility0.0004995

Abundances
% in UniverseN/A
% in SunN/A
% in MeteoritesN/A
% in Earth's Crust9.9×10-13%
% in Oceans2×10-23%
% in Humans0%

Atomic dimensions and structure
Atomic RadiusN/A
Covalent Radius200 pm
Van der Waals RadiusN/A
Crystal StructureCentered Tetragonal
Lattice Angles
π/2, π/2, π/2
Lattice Constants
392.5, 392.5, 323.8 pm
Space Group NameI4/mmm
Space Group Number139

Nuclear Properties
Half-Life32787.92491121 y
Lifetime47279.29984779 y
Decay ModeAlphaEmission
Quantum Numbers4K11/2
Neutron Cross Section200
Neutron Mass AbsorptionN/A
Known Isotopes
212Pa, 213Pa, 214Pa, 215Pa, 216Pa, 217Pa, 218Pa, 219Pa, 220Pa, 221Pa, 222Pa, 223Pa, 224Pa, 225Pa, 226Pa, 227Pa, 228Pa, 229Pa, 230Pa, 231Pa, 232Pa, 233Pa, 234Pa, 235Pa, 236Pa, 237Pa, 238Pa, 239Pa, 240Pa
Stable Isotopes
None
Isotopic Abundances


Notes on the properties of Protactinium:

Atomic Mass: Atomic mass number given for longest lived isotope.

Specific Heat: Value given for gas phase.

Up to date, curated data provided by Mathematica's ElementData function from Wolfram Research, Inc.

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