Properties of Cesium (Cs)
Cesium is a chemical element with the symbol (Cs) and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28.5 degrees Celsius (83.3 degrees Fahrenheit), which is just above room temperature. Cesium is one of the most reactive elements and is known for its rapid and vigorous reactions with air and water.
The following table provides a comprehensive list of cesium (Cs) 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 |
|---|---|
| Crystal Structure | Body-centered cubic (bcc) |
| Atomic Number | 55 |
| Molar Mass | 132.905 g/mol |
| Density | 1873 kg/m3 |
| Mechanical Properties | Metric |
| Young’s Modulus (E) | 1.69 GPa |
| Shear Modulus (G) | 0.67 GPa |
| Bulk Modulus (K) | 2.693 GPa |
| Poisson’s Ratio (ν) | 0.295 |
| Mohs Hardness | 0.2 |
| Thermal Properties | Metric |
| Melting Point | 28.5 °C |
| Boiling Point | 671 °C |
| Thermal Conductivity (27°C) | 35.9 W/m·K |
| Specific Heat Capacity (Cp) (25°C) | 242 J/kg·K |
| Coefficient of Thermal Expansion (αL) (25°C) | 9.7×10-5 1/°C |
| Electrical Properties | Metric |
| Electrical Resistivity | 2.08×10-5 Ω·cm |
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) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.