PROTACTINIUM, Pa (91)

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ATOMIC ARCHITECTURE

Spectrograph
Elemental Tile
Protactinium Torbernite
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PROTACTINIUM

Pa (91)

ˌprəʊtækˈtɪniəm

PHONETICS

Protactinium is a dense, silvery-grey metal which readily reacts with oxygen, water vapour and inorganic acids. The average concentrations in the Earth’s crust is in the order of a few parts per trillion, but may reach up to a few parts per million in some uraninite ore deposits. Due to its scarcity, high radioactivity and high toxicity, there are currently no uses for protactinium outside of scientific research, and for this purpose, protactinium is mostly extracted from spent nuclear fuel.

ELEMENT BRIEF

1913 by Otto Hahn, Lise Meitner, Frederick Soddy and John Cranston, Germany.

DISCOVERY

Greek 'protos' meaning 'first'.

ETYMOLOGY

Protactinium

ELEMENT

Pa

SYMBOL

91

ATOMIC NUMBER

7440-13-3

CAS NUMBER
element

ELEMENTAL SPECTRUM


Silver

ELEMENTAL COLOUR


-

REFRACTIVE INDEX


-

POISSON RATIO


15.032 cm³

MOLAR VOLUME


-

BRINELL HARDNESS


-

MOHS HARDNESS


-

VICKERS HARDNESS


-

SPEED OF SOUND


-

BULK MODULUS


-

SHEAR MODULUS


-

YOUNG MODULUS


ALLOTROPES

element element

1,845.15 K, 1,572.00 °C

MELTING POINT


5,093.15 K, 4,820.00 °C

BOILING POINT


4,273.15 K, 4,000.00 °C

AUTOMATIC IGNITION


-

FLASHPOINT


-

CRITICAL TEMPERATURE


-

CRITICAL PRESSURE


47.000'000 W/(m K)

THERMAL CONDUCTIVITY


-

THERMAL EXPANSION


99.10 J/(kg K)

SPECIFIC HEAT


15.000 kJ/mol

HEAT FUSION


470.000 kJ/mol

HEAT VAPORISATION


-

HEAT COMBUSTION


-

CURIE POINT


-

NEEL POINT


-

ADIABATIC INDEX


Solid

PHASE

Conductor

ELECTRICAL TYPE


5.60M S/m

CONDUCTIVITY


180.00n Ω.m

RESISTIVITY


1.400 K

SUPERCONDUCTING POINT


-

MAGNETIC TYPE


0.000'000'032'5

MASS SUSCEPTIBILITY


0.000'000'007'509'00

MOLAR SUSCEPTIBILITY


0.000'499'500'00

VOLUME SUSCEPTIBILITY

Actinide

CLASSIFICATION


231.035'884'2

ATOMIC WEIGHT


161 pm

ATOMIC RADIUS


169 pm

COVALENT RADIUS SINGLE BOND


138 pm

COVALENT RADIUS DOUBLE BOND


129 pm

COVALENT RADIUS TRIPLE BOND


243 pm

VAN DER WAALS RADIUS


[Rn]7s²5f²6d¹

ELECTRON CONFIGURATION


Tetragonal, Primitive

CRYSTAL STRUCTURE


15.370'00 g/cm³

DENSITY AS SOLID


-

DENSITY AS LIQUID


-

DENSITY AS GAS


I4/mmm

SPACE GROUP NAME


139

SPACE GROUP NUMBER


π/2, π/2 π/2

LATTICE ANGLES


392.5, 392.5 323.8 pm

LATTICE CONSTANTS

5

VALENCE


1.5

ELECTRONEGATIVITY


-

ELECTRON AFFINITY


IONISATION ENERGY

element

-

UNIVERSE


-

METEORITES


-

SUN


0.000'000'000'81 %

EARTH CRUST


2 x 10¯²³ %

OCEANS


-

HUMANS

32,788 years

HALF LIFE


47,279 years

LIFETIME


6d¹ = 6, 2, -2, +1/2

QUANTUM NUMBERS


10.500'00 b σs

NEUTRON CROSS SECTION


200.600'00 b σa

NEUTRON MASS ABSORPTION


STABLE ISOTOPES

NONE


UNSTABLE ISOTOPES

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ISOTOPIC CHAIN

CENTRALDATACORE

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