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potassium
Image: Wikimedia Commons

potassium

Chemical element with symbol K and atomic number 19

Chemical elementchemical elementlithophile elementactive metalQ703

Also known as 19K · element 19 · K

Symbol
Atomic number
  • 19
Mass
Melting point
Boiling point
Density
Discovered by
Discovered
  • 1807

Overview

All data

163 statements · 31% with external sources · numbers in brackets are citations

Oxidation state
Subclass of
Different from
Named after
Formula
Canonical SMILES
Standard molar entropy
Electronegativity
  • 0.82
Vapor pressure
Safety classification and labelling
Part of
Unicode character
Electron configuration
  • [Ar] 4s¹
  • 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Ionic radius
  • 1.37 ångström charge number: 1 · coordination number: 4
  • 1.38 ångström charge number: 1 · coordination number: 6
  • 1.51 ångström charge number: 1 · coordination number: 8
  • 1.64 ångström charge number: 1 · coordination number: 12
Found in taxon
Show 4 more
Space group
Crystal system
Thermal conductivity
  • 100 watt per metre kelvin
Specific heat capacity
  • 757.8 joule per kilogram kelvin
Speed of sound
  • 2,000 m/s
Electrical resistivity
  • 7.2e-8 ohm metre
Point group
Standard enthalpy of formation
  • 89 kilojoule per mole state of matter: gas
  • 2.27 kilojoule per mole state of matter: liquid
Has characteristic
Linear thermal expansion coefficient
  • 77.37 micrometre per metre kelvin temperature: 20°C
Ionization energy
Atomic radius
  • 220 picometre
Covalent radius
  • 203 picometre
Van der Waals radius
  • 275 picometre

On other databases

88 identifiers linking potassium across the web's reference databases