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Technical data for Iodine

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

Overview
NameIodine
SymbolI
Atomic Number53
Atomic Weight126.90447
Density4.94 g/cm3
Melting Point113.7 °C
Boiling Point184.3 °C

Thermal properties
PhaseSolid
Melting Point113.7 °C
Boiling Point184.3 °C
Absolute Melting Point386.85 K
Absolute Boiling Point457.4 K
Critical Pressure11.7 MPa (115.5 Atm)
Critical Temperature819 K
Heat of Fusion7.76 kJ/mol
Heat of Vaporization20.9 kJ/mol
Heat of CombustionN/A
Specific Heat429 J/(kg K)[note]
Adiabatic IndexN/A
Neel PointN/A
Thermal Conductivity0.449 W/(m K)
Thermal ExpansionN/A

Bulk physical properties
Density4.94 g/cm3
Density (Liquid)N/A
Molar Volume0.000025689
Brinell HardnessN/A
Mohs HardnessN/A
Vickers HardnessN/A
Bulk Modulus7.7 GPa
Shear ModulusN/A
Young ModulusN/A
Poisson RatioN/A
Refractive IndexN/A
Speed of SoundN/A
Thermal Conductivity0.449 W/(m K)
Thermal ExpansionN/A

Reactivity
Valence7
Electronegativity2.66
ElectronAffinity295.2 kJ/mol
Ionization Energies
1008.4, 1845.9, 3180 kJ/mol

Health and Safety
Autoignition PointN/A
FlashpointN/A
Heat of CombustionN/A
DOT Hazard Class8
DOT Numbers1759
EU NumberN/A
NFPA Fire Rating0
NFPA HazardsN/A
NFPA Health Rating3
NFPA Reactivity Rating0
RTECS NumberRTECSNN1575000
NFPA LabelNFPA Label

Classifications
Alternate NamesNone
Names of AllotropesDiiodine
Blockp
Group17
Period5
Electron Configuration[Kr]4d105s25p5
ColorSlateGray
Discovery
1811 in France
Gas phaseN/A
CAS NumberCAS7553-56-2
CID NumberCID807
Gmelin NumberN/A
NSC NumberN/A
RTECS NumberRTECSNN1575000

Electrical properties
Electrical TypeInsulator
Electrical Conductivity1×10-7 S/m
Resistivity1×107 m Ω
Superconducting PointN/A

Magnetic properties
Magnetic TypeDiamagnetic
Curie PointN/A
Mass Magnetic Susceptibility-4.5×10-9
Molar Magnetic Susceptibility-1.14×10-9
Volume Magnetic Susceptibility-0.0000222

Abundances
% in Universe1×10-7%
% in SunN/A
% in Meteorites0.000025%
% in Earth's Crust0.000049%
% in Oceans6×10-6%
% in Humans0.00002%

Atomic dimensions and structure
Atomic Radius115 pm
Covalent Radius133 pm
Van der Waals Radius198 pm
Crystal StructureBase Centered Orthorhombic
Lattice Angles
π/2, π/2, π/2
Lattice Constants
718.02, 471.02, 981.03 pm
Space Group NameCmca
Space Group Number64

Nuclear Properties
Half-LifeStable
LifetimeStable
Decay ModeN/A
Quantum Numbers2P3/2
Neutron Cross Section6.2
Neutron Mass Absorption0.0018
Known Isotopes
108I, 109I, 110I, 111I, 112I, 113I, 114I, 115I, 116I, 117I, 118I, 119I, 120I, 121I, 122I, 123I, 124I, 125I, 126I, 127I, 128I, 129I, 130I, 131I, 132I, 133I, 134I, 135I, 136I, 137I, 138I, 139I, 140I, 141I, 142I, 143I, 144I
Stable Isotopes
127I
Isotopic Abundances
127I100%


Notes on the properties of Iodine:

Specific Heat: Value given for solid phase.

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

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