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hydrogen
Image: Wikimedia Commons

hydrogen

Chemical element with symbol H and atomic number 1

Chemical elementchemical elementatmophile elementQ556

Also known as element 1

Symbol
Atomic number
Mass
Melting point
Boiling point
Density
Discovered by
Discovered
  • 1766

Overview

All data

159 statements · 20% with external sources · numbers in brackets are citations

Oxidation state
  • -1
  • 1
  • 0
Electronegativity
  • 2.2
Different from
Location of discovery
Subclass of
Color
Permanent duplicated item
Part of
Refractive index
Speed of sound
Thermal conductivity
Ionization energy
Molar enthalpy of vaporization
Half-life
Named after
Electron configuration
  • 1s¹
Has use
Ionic radius
  • 54 picometre charge number: 1
Unicode character
  • 氫
Native label
  • Waasserstoff
  • Hydrogène
Specific heat capacity
  • 14,304 joule per kilogram kelvin
Standard enthalpy of formation
  • 217.998 kilojoule per mole state of matter: gas
Standard molar entropy
  • 114.717 joule per mole kelvin state of matter: gas
Has characteristic
Crystal system
Atomic radius
  • 53 picometre
  • 25 picometre
Covalent radius
  • 31 picometre
  • 31 picometre
Van der Waals radius
  • 120 picometre

On other databases

86 identifiers linking hydrogen across the web's reference databases