Technical data for Beryllium

Overview Name Beryllium Symbol Be Atomic Number 4 Atomic Weight 9.012182 Density 1.848 g/cm3 Melting Point 1287 °C Boiling Point 2470 °C Thermal properties Phase Solid Melting Point 1287 °C Boiling Point 2470 °C Absolute Melting Point 1560 K Absolute Boiling Point 2743 K Critical Pressure N/A Critical Temperature N/A Heat of Fusion 7.95 kJ/mol Heat of Vaporization 297 kJ/mol Heat of Combustion N/A Specific Heat 1820 J/(kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 190 W/(m K) Thermal Expansion 0.0000113 K-1 Bulk physical properties Density 1.848 g/cm3 Density (Liquid) 1.69 g/cm3 Molar Volume 4.8767×10-6 Brinell Hardness 600 MPa Mohs Hardness 5.5 MPa Vickers Hardness 1670 MPa Bulk Modulus 130 GPa Shear Modulus 132 GPa Young Modulus 287 GPa Poisson Ratio 0.032 Refractive Index N/A Speed of Sound 1.3×104 m/s Thermal Conductivity 190 W/(m K) Thermal Expansion 0.0000113 K-1 Reactivity Valence 2 Electronegativity 1.57 ElectronAffinity 0 kJ/mol Ionization Energies 899.5, 1757.1, 14848.7, 21006.6 kJ/mol Health and Safety Autoignition Point N/A Flashpoint N/A Heat of Combustion N/A DOT Hazard Class 6.1 DOT Numbers 1567 EU Number N/A NFPA Fire Rating 1 NFPA Hazards N/A NFPA Health Rating 3 NFPA Reactivity Rating 0 RTECS Classes Tumorigen, Mutagen RTECS Number RTECSDS1750000 NFPA Label

Classifications Alternate Names None Names of Allotropes None Block s Group 2 Period 2 Electron Configuration [He]2s2 Color SlateGray Discovery 1797 in France Gas phase N/A CAS Number CAS7440-41-7 CID Number CID5460467 Gmelin Number N/A NSC Number N/A RTECS Number RTECSDS1750000 Electrical properties Electrical Type Conductor Electrical Conductivity 2.5×107 S/m Resistivity 4×10-8 m Ω Superconducting Point 0.026 Magnetic properties Magnetic Type Diamagnetic Curie Point N/A Mass Magnetic Susceptibility -1.26×10-8 Molar Magnetic Susceptibility -1.136×10-10 Volume Magnetic Susceptibility -0.00002328 Abundances % in Universe 1×10-7% % in Sun 1×10-8% % in Meteorites 2.9×10-6% % in Earth's Crust 0.00019% % in Oceans 6×10-11% % in Humans 4×10-8% Atomic dimensions and structure Atomic Radius 112 pm Covalent Radius 90 pm Van der Waals Radius N/A Crystal Structure Simple Hexagonal Lattice Angles π/2, π/2, 2 π/3 Lattice Constants 228.58, 228.58, 358.43 pm Space Group Name P63/mmc Space Group Number 194 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 1S0 Neutron Cross Section 0.0092 Neutron Mass Absorption 0.00003 Known Isotopes 5Be, 6Be, 7Be, 8Be, 9Be, 10Be, 11Be, 12Be, 13Be, 14Be, 15Be, 16Be Stable Isotopes 9Be Isotopic Abundances 9Be 100%