Periodic Table of Elements https://periodic-table.pro/Element/Th/enView online at https://periodic-table.pro Thorium This foil is what remains after useful shapes were stamped out, but what those shapes were useful for remains a mystery. Pure thorium metal like this is quite rare, and not easily obtained. 01. OVERVIEW Symbol Th Atomic number 90 Atomic weight 232.0381 Density 11.724 g/cm³ Melting point 1750 °C Boiling point 4820 °C 02. THERMAL PROPERTIES Phase Solid Melting point 1750 °C Boiling point 4820 °C Absolute melting point 2023 K Absolute boiling point 5093 K Critical pressure N/A Critical temperature N/A Heat of fusion 16 kJ/mol Heat of vaporization 530 kJ/mol Heat of combustion N/A Specific heat 118 J/(kg K) Adiabatic index N/A Neel point N/A Thermal conductivity 54 W/(m K) Thermal expansion 0.000011 K¹ 03. PHYSICAL PROPERTIES Density 11.724 g/cm³ Density (liquid) N/A Molar volume 0.0000197917 Molar mass 232.03806 u Brinell hardness 400 MPa Mohs hardness 3 MPa Vickers hardness 350 MPa Bulk modulus 54 GPa Shear modulus 31 GPa Young modulus 79 GPa Poisson ratio 0.27 Refractive index N/A Speed of sound 2490 m/s Thermal conductivity 54 W/(m K) Thermal expansion 0.000011 K¹ 04. REACTIVITY Valence 4 Electronegativity 1.3 Electron affinity N/A Ionization energies 587, 1110, 1930, 2780 kJ/mol 05. SAFETY Autoignition point 130 °C Flashpoint N/A Heat of combustion N/A 06. CLASSIFICATIONS Alternate names N/A Names of allotropes N/A Block, Group, Period f, N/A, 7 Electron configuration [Rn]6d²7s² Color Silver Discovery 1829 in Sweden Gas phase N/A 07. ELECTRICAL PROPERTIES Electrical type Conductor Electrical conductivity 6.7×10⁶ S/m Resistivity 1.5×10⁷ m Ω Superconducting point 1.38 08. MAGNETIC PROPERTIES Magnetic type Paramagnetic Curie point N/A Mass magnetic susceptibility 7.2×10⁹ m³/Kg Molar magnetic susceptibility 1.7×10⁹ m³/mol Volume magnetic susceptibility 0.000084 09. ABUNDANCES In universe 4×10⁸% In sun 3×10⁸% In meteorites 3.9×10⁶% In earth's crust 0.00% In oceans 4×10¹²% In humans N/A 10. ATOMIC DIMENSIONS AND STRUCTURE Atomic radius N/A Covalent radius N/A Van der Waals radius N/A Crystal structure Face Centered Cubic Lattice angles π/2, π/2, π/2 Lattice constants 508.42, 508.42, 508.42 pm Space group name Fm_ 3m Space group number 225 11. NUCLEAR PROPERTIES Half-Life 1.406×10¹⁰ y Lifetime 2.0285×10¹⁰ y Decay mode Alpha emission Quantum numbers ³F₂ Neutron cross section 7.4 Neutron mass absorption 0.001 Known Isotopes ²⁰⁹Th, ²¹⁰Th, ²¹¹Th, ²¹²Th, ²¹³Th, ²¹⁴Th, ²¹⁶Th, ²¹⁷Th, ²¹⁸Th, ²¹⁹Th, ²²⁰Th, ²²¹Th, ²²³Th, ²²⁴Th, ²²⁵Th, ²²⁶Th, ²²⁷Th, ²²⁸Th, ²³⁰Th, ²³¹Th, ²³²Th, ²³³Th, ²³⁴Th, ²³⁵Th, ²³⁷Th, ²³⁸Th Stable Isotopes ²³²Th Isotopic Abundances ²³²Th - 100% https://periodic-table.pro/Element/Th/enView online at https://periodic-table.pro.