Technical data for Potassium

Overview Name Potassium Symbol K Atomic Number 19 Atomic Weight 39.0983 Density 0.856 g/cc Melting Point 63.38°C Boiling Point 759.°C Thermal properties Phase Solid Melting Point 63.38°C Boiling Point 759.°C Absolute Melting Point 336.53K Absolute Boiling Point 1032.K Critical Pressure 16.MPa (157.9Atm)[note] Critical Temperature 2223.K[note] Heat of Fusion 2.33KJ/mol Heat of Vaporization 76.9KJ/mol Heat of Combustion -182.J/(Kg K) Specific Heat 757.J/(Kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 100.W/(m K) Thermal Expansion N/A Bulk physical properties Density 0.856 g/cc Density (Liquid) 0.828 g/cc Molar Volume 0.00004568 Brinell Hardness 0.363MPa Mohs Hardness 0.4MPa Vickers Hardness N/A Bulk Modulus 3.1GPa Shear Modulus 1.3GPa Young Modulus N/A Poisson Ratio N/A Refractive Index N/A Speed of Sound 2.×103m/s Thermal Conductivity 100.W/(m K) Thermal Expansion N/A Reactivity Valence 1 Electronegativity 0.82 ElectronAffinity 48.4KJ/mol Ionization Energies 418.8, 3052., 4420., 5877., 7975., 9590., 11343., 14944., 16963.7, 48610. KJ/mol Health and Safety Autoignition Point 440.°C Flashpoint N/A Heat of Combustion -182.J/(Kg K) DOT Hazard Class 4.3 DOT Numbers 2257 EU Number EU231-119-8 NFPA Fire Rating 3 NFPA Hazards Water Reactive NFPA Health Rating 3 NFPA Reactivity Rating 2 RTECS Classes Other RTECS Number RTECSTS6460000 NFPA Label

Classifications Alternate Names Kalium Names of Allotropes None Block s Group 1 Period 4 Electron Configuration [Ar]4s1 Color Silver Discovery 1807 in United Kingdom Gas phase N/A CAS Number CAS7440-09-7 CID Number CID813 Gmelin Number Gmelin15203 NSC Number N/A RTECS Number RTECSTS6460000 Electrical properties Electrical Type Conductor Electrical Conductivity 1.4×107S/m Resistivity 7.×10-8m Ω Superconducting Point N/A Magnetic properties Magnetic Type N/A Curie Point N/A Mass Magnetic Susceptibility 6.7×10-9 Molar Magnetic Susceptibility 2.62×10-10 Volume Magnetic Susceptibility 5.74×10-6 Abundances % in Universe 0.0003% % in Sun 0.0004% % in Meteorites 0.07% % in Earth's Crust 1.5% % in Oceans 0.042% % in Humans 0.2% Atomic dimensions and structure Atomic Radius 243.pm Covalent Radius 196.pm Van der Waals Radius 275.pm Crystal Structure Body Centered Cubic Lattice Angles π/2, π/2, π/2 Lattice Constants 532.8, 532.8, 532.8 pm Space Group Name Im_ 3m Space Group Number 229 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 2S1/2 Neutron Cross Section 2.1 Neutron Mass Absorption 0.0018 Known Isotopes 32K, 33K, 34K, 35K, 36K, 37K, 38K, 39K, 40K, 41K, 42K, 43K, 44K, 45K, 46K, 47K, 48K, 49K, 50K, 51K, 52K, 53K, 54K, 55K Stable Isotopes 39K, 41K Isotopic Abundances 39K 93.2581% 40K 0.0117% 41K 6.7302%