1Gas
H 1.008 Atomic mass · uNonmetals
Hydrogen
Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.
Discovery 1766 (Henry Cavendish)
K1
Physical properties
Values for the element in its standard state.
- Density
- 0.0000899g/cm³
- Melting point
- 14K
- Boiling point
- 20K
- Atomic radius
- 37pm
- Bonding type
- Diatomic
- Molar heat
- 28.836J/(mol·K)
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 1 electrons;
All electrons are already written explicitly.
1 electrons Orbital order preserved from source
- Electronegativity
- 2.2Pauling scale
- First ionization energy
- 1,312kJ/mol
- Electron affinity
- 73kJ/mol
- Van der Waals radius
- 120pm
H HydrogenAtomic number 1
1,312kJ/mol
Atomic numberGaps indicate unavailable data
About hydrogen
- Appearance
- Colorless gas
- Discovery
- 1766 (Henry Cavendish)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.