Properties of Krypton (Kr)

Krypton is a chemical element with the symbol Kr and atomic number 36. It belongs to the noble gases group on the periodic table. Krypton is a colorless, odorless gas that is relatively rare in Earth’s atmosphere, making up only a small fraction of the air.

The following table provides a comprehensive list of krypton 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.

Table of Krypton Properties
Physical Properties
Metric
Molar Mass83.798 g/mol
Density (0°C)3.733 kg/m3
Dynamic Viscosity (25°C)25.5 µPa·s
Speed of Sound in Gas (30°C)224 m/s
Thermal PropertiesMetric
Melting Point-157.4 °C
Boiling Point-153.4 °C
Thermal Conductivity (25°C)9.5×10-3 W/m·K
Specific Heat Capacity (Cp)248 J/kg·K
Critical ConstantsMetric
Critical Temperature (Tc)-63.7 °C
Critical Pressure (Pc)5.5 MPa
Critical Density (ρc)908 kg/m3
Electrical PropertiesMetric
Relative Permittivity (εr)1.000784
Optical PropertiesMetric
Refractive Index (589 nm)1.000427

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)

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.