Caesium, Cs (55)

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ATOMIC ARCHITECTURE

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Caesium
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CAESIUM

Cs (55)

ˈsiːziəm

PHONETICS

Caesium is highly reactive and ignites spontaneously in air and explosively with water even at low temperatures. Since 1990, the largest application of the element has been as caesium formate for drilling fluids and has a range of applications in the production of electricity, in electronics, and in chemistry.

ELEMENT BRIEF

1860 by Gustav Kirchhoff and Robert Bunsen, Germany.

DISCOVERY

Latin, 'caesius' meaning “sky blue” or 'heavenly blue'.

ETYMOLOGY

Caesium

ELEMENT

Cs

SYMBOL

55

ATOMIC NUMBER

7440-46-2

CAS NUMBER
element

ELEMENTAL SPECTRUM


Silver

ELEMENTAL COLOUR


-

REFRACTIVE INDEX


-

POISSON RATIO


70.732 cm³

MOLAR VOLUME


140.00k Pa, 1.381'7 Atm

BRINELL HARDNESS


0.20

MOHS HARDNESS


-

VICKERS HARDNESS


1,651 m/s, Mach 4.813'4

SPEED OF SOUND


1.60G Pa, 15.790'8k Atm

BULK MODULUS


-

SHEAR MODULUS


1.70G Pa, 16.777'7k Atm

YOUNG MODULUS


ALLOTROPES

element element element element

301.59 K, 28.44 °C

MELTING POINT


944.15 K, 671.00 °C

BOILING POINT


-

AUTOMATIC IGNITION


-

FLASHPOINT


1,938.00 K, 1,664.85 °C

CRITICAL TEMPERATURE


9.40M Pa, 93 Atm

CRITICAL PRESSURE


36.000'000 W/(m K)

THERMAL CONDUCTIVITY


-

THERMAL EXPANSION


242.00 J/(kg K)

SPECIFIC HEAT


2.090 kJ/mol

HEAT FUSION


65.000 kJ/mol

HEAT VAPORISATION


-

HEAT COMBUSTION


-

CURIE POINT


-

NEEL POINT


-

ADIABATIC INDEX


Solid

PHASE

Conductor

ELECTRICAL TYPE


5.00M S/m

CONDUCTIVITY


200.00n Ω.m

RESISTIVITY


-

SUPERCONDUCTING POINT


-

MAGNETIC TYPE


-0.000'000'002'8

MASS SUSCEPTIBILITY


-0.000'000'000'372'00

MOLAR SUSCEPTIBILITY


-0.000'005'260'00

VOLUME SUSCEPTIBILITY

Alkali Metal

CLASSIFICATION


132.905'451'9

ATOMIC WEIGHT


298 pm

ATOMIC RADIUS


232 pm

COVALENT RADIUS SINGLE BOND


209 pm

COVALENT RADIUS DOUBLE BOND


-

COVALENT RADIUS TRIPLE BOND


343 pm

VAN DER WAALS RADIUS


[Xe]6s¹

ELECTRON CONFIGURATION


Cubic, Face-centred

CRYSTAL STRUCTURE


1.879'00 g/cm³

DENSITY AS SOLID


1.843'00 g/cm³

DENSITY AS LIQUID


5.900'00 g/cm³

DENSITY AS GAS


lm_3m

SPACE GROUP NAME


229

SPACE GROUP NUMBER


π/2, π/2 π/2

LATTICE ANGLES


614.1, 614.1 614.1 pm

LATTICE CONSTANTS

1

VALENCE


0.79

ELECTRONEGATIVITY


45.51 kJ/mol

ELECTRON AFFINITY


IONISATION ENERGY

element element

0.000'000'1 %

UNIVERSE


0.000'014 %

METEORITES


0.000'000'8 %

SUN


0.000'000'8 %

EARTH CRUST


0.000'000'05 %

OCEANS


0.000'002 %

HUMANS

Stable

HALF LIFE


Stable

LIFETIME


6s¹ = 6, 0, 0, +1/2

QUANTUM NUMBERS


3.900'00 b σs

NEUTRON CROSS SECTION


29.000'00 b σa

NEUTRON MASS ABSORPTION


STABLE ISOTOPES

element

UNSTABLE ISOTOPES

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ISOTOPIC CHAIN

CENTRALDATACORE

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