| Overview |
| Name | Hydrogen |
| Symbol | H |
| Atomic Number | 1 |
| Atomic Weight | 1.00794 |
| Density | 0.0899 g/l[note] |
| Melting Point | -259.14 °C |
| Boiling Point | -252.87 °C |
Thermal properties |
| Phase | Gas |
| Melting Point | -259.14 °C |
| Boiling Point | -252.87 °C |
| Absolute Melting Point | 14.01 K |
| Absolute Boiling Point | 20.28 K |
| Critical Presure | 1.293 MPa (12.76 Atm) |
| Critical Temperature | 32.97 K |
| Heat of Fusion | 0.558 kJ/mol |
| Heat of Vaporization | 0.452 kJ/mol |
| Heat of Combustion | N/A |
| Specific Heat | 14300 J/(kg K)[note] |
| Adiabatic Index | 7/5 |
| Thermal Conductivity | 0.1805 W/(m K) |
| Thermal Expansion | N/A |
Bulk physical properties |
| Density | 0.0899 g/l[note] |
| Density (Liquid) | N/A |
| Molar Volume | 0.01121 |
| Refractive Index | 1.000132 |
| Speed of Sound | 1270 m/s |
| Thermal Conductivity | 0.1805 W/(m K) |
| Thermal Expansion | N/A |
Reactivity |
| Valence | 1 |
| Electronegativity | 2.2 |
| ElectronAffinity | 72.8 kJ/mol |
| Ionization Energies | |
Health and Safety |
| Autoignition Point | 535.5 °C |
| Flashpoint | -18 °C |
|
Classifications |
| Alternate Names | None |
| Nams of Allotropes | Dihydrogen |
| Block | s |
| Group | 1 |
| Period | 1 |
| Electron Configuration | 1s1 |
| Color | Colorless |
| Discovery | |
| Gas phase | Diatomic |
| CAS Number | CAS1333-74-0 |
Electrical properties |
| Electrical Type | N/A |
| Electrical Conductivity | N/A |
| Resistivity | N/A |
| Superconducting Point | N/A |
Magnetic properties |
| Magnetic Type | Diamagnetic |
| Curie Point | N/A |
| Mass Magnetic Susceptibility | -2.48×10-8 |
| Molar Magnetic Susceptibility | -2.5×10-11 |
| Volume Magnetic Susceptibility | -2.23×10-9 |
Abundances |
| % in Universe | 75% |
| % in Sun | 75% |
| % in Meteorites | 2.4% |
| % in Earth's Crust | 0.15% |
| % in Oceans | 11% |
| % in Humans | 10% |
Atomic dimensions and structure |
| Atomic Radius | 53 pm |
| Covalent Radius | 37 pm |
| Van der Waals Radius | 120 pm |
| Crystal Structure | Simple Hexagonal |
| Lattice Angles | |
| Lattice Constants | |
| Space Group Name | P63/mmc |
| Space Group Number | 194 |
Nuclear Properties |
| Half-Life | Stable |
| Lifetime | Stable |
| Quantum Numbers | 2S1/2 |
| Neutron Cross Section | 0.332 |
| Neutron Mass Absorption | 0.011 |
| Stable Isotopes | |
| Isotopic Abundances | |
|