Technical data for Iodine

Overview Name Iodine Symbol I Atomic Number 53 Atomic Weight 126.90447 Density 4.94 g/cm3 Melting Point 113.7 °C Boiling Point 184.3 °C Thermal properties Phase Solid Melting Point 113.7 °C Boiling Point 184.3 °C Absolute Melting Point 386.85 K Absolute Boiling Point 457.4 K Critical Pressure 11.7 MPa (115.5 Atm) Critical Temperature 819 K Heat of Fusion 7.76 kJ/mol Heat of Vaporization 20.9 kJ/mol Specific Heat 429 J/(kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 0.449 W/(m K) Thermal Expansion N/A Bulk physical properties Density 4.94 g/cm3 Density (Liquid) N/A Molar Volume 0.000025689 Brinell Hardness N/A Mohs Hardness N/A Vickers Hardness N/A Bulk Modulus 7.7 GPa Shear Modulus N/A Young Modulus N/A Poisson Ratio N/A Refractive Index N/A Speed of Sound N/A Thermal Conductivity 0.449 W/(m K) Thermal Expansion N/A Reactivity Valence 7 Electronegativity 2.66 ElectronAffinity 295.2 kJ/mol Ionization Energies 1008.4, 1845.9, 3180 kJ/mol Health and Safety DOT Hazard Class 8 DOT Numbers 1759 RTECS Number RTECSNN1575000 NFPA Label

Classifications Alternate Names None Names of Allotropes Diiodine Block p Group 17 Period 5 Series Halogen Electron Configuration [Kr]5s24d105p5 Color SlateGray Discovery 1811 in France Gas phase N/A CAS Number CAS7553-56-2 CID Number CID807 RTECS Number RTECSNN1575000 Electrical properties Electrical Type Insulator Electrical Conductivity 1×10-7 S/m Resistivity 1×107 m Ω Superconducting Point N/A Magnetic properties Magnetic Type Diamagnetic Curie Point N/A Mass Magnetic Susceptibility -4.5×10-9 m3/Kg Molar Magnetic Susceptibility -1.14×10-9 m3/mol Volume Magnetic Susceptibility -0.0000222 Abundances % in Universe 1×10-7% % in Sun N/A % in Meteorites 0.000025% % in Earth's Crust 0.000049% % in Oceans 6×10-6% % in Humans 0.00002% Atomic dimensions and structure Atomic Radius 115 pm Covalent Radius 139 pm Van der Waals Radius 198 pm Crystal Structure Base Orthorhombic Lattice Angles π/2, π/2, π/2 Lattice Constants 718.02, 471.02, 981.03 pm Space Group Name Cmca Space Group Number 64 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 2P3/2 Neutron Cross Section 6.3 Neutron Mass Absorption 0.0018 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 127I 100%