Properties of Deuterium (D2)
Deuterium is a stable isotope of hydrogen. It has one proton and one neutron in its nucleus, while the nucleus of ordinary hydrogen (protium) has only one proton. Deuterium is also known as heavy hydrogen because it is twice as heavy as protium. Deuterium is often used in nuclear fusion reactions and can be found in small amounts in naturally occurring water.
The following table provides a comprehensive list of deuterium properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the icon to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Molar Mass | 4.028 g/mol |
| Density (0°C) | 0.0899 kg/m3 |
| Dynamic Viscosity (25°C) | 12.6 µPa·s |
| Speed of Sound in Gas (0°C) | 888 m/s |
| Thermal Properties | Metric |
| Melting Point | -254.4 °C |
| Boiling Point | -249.5 °C |
| Thermal Conductivity (25°C) | 0.134 W/m·K |
| Specific Heat Capacity (Cp) | 7248 J/kg·K |
| Critical Constants | Metric |
| Critical Temperature (Tc) | -234.8 °C |
| Critical Pressure (Pc) | 1.66 MPa |
| Critical Density (ρc) | 66.9 kg/m3 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.0001265 |
| Hazardous Data | Metric |
| Autoignition Temperature | 560 °C |
| Lower Flammability Limit | 6.6% |
| Upper Flammability Limit | 79.6% |
| NFPA Rating (Health) | 0 |
| NFPA Rating (Fire) | 4 |
| NFPA Rating (Reactivity) | 0 |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) Yaws, Carl L. The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. Netherlands: Elsevier Science, 2015. 4) Fire Protection Guide to Hazardous Materials, 14th Edition. United States: National Fire Protection Association, 2010.