Technical data for Protactinium

Overview
NameProtactinium
SymbolPa
Atomic Number91
Atomic Weight231.03588
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
Heat of Fusion15 kJ/mol
Heat of Vaporization470 kJ/mol
Heat of CombustionN/A
Specific Heat99.1 J/(kg K)[note]
Thermal Conductivity47 W/(m K)
Thermal ExpansionN/A

Bulk physical properties
Density15.37 g/cm3
Density (Liquid)N/A
Molar Volume0.0000150316
Thermal Conductivity47 W/(m K)
Thermal ExpansionN/A

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

Health and Safety
Autoignition PointN/A
FlashpointN/A

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blockf
GroupN/A
Period7
Electron Configuration[Rn]5f26d17s2
ColorSilver
Discovery
1913 in Germany and United Kingdom
Gas phaseN/A
CAS NumberCAS7440-13-3

Electrical properties
Electrical TypeConductor
Electrical Conductivity5.6×106 S/m
Resistivity1.8×10-7 m Ω
Superconducting Point1.4

Magnetic properties
Magnetic TypeN/A
Curie PointN/A
Mass Magnetic Susceptibility3.25×10-8
Molar Magnetic Susceptibility7.509×10-9
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 HumansNone

Atomic dimensions and structure
Atomic RadiusN/A
Covalent RadiusN/A
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-Life32788 y
Lifetime47279 y

Notes on the properties of Protactinium:
Specific Heat: Value given for gas phase.