Properties of Neptunium (Np)
Neptunium is a chemical element with the symbol (Np) and atomic number 93. It is a radioactive metal and is part of the actinide series. Neptunium was the first transuranium element to be synthesized artificially, and it plays a role in nuclear reactions and the production of plutonium in nuclear reactors.
The following table provides a comprehensive list of neptunium (Np) 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 | Orthorhombic |
| Atomic Number | 93 |
| Molar Mass | 237.0482 g/mol |
| Density | 20250 kg/m3 |
| Mechanical Properties | Metric |
| Young’s Modulus (E) | 68 GPa |
| Thermal Properties | Metric |
| Melting Point | 640 °C |
| Boiling Point | 3902 °C |
| Thermal Conductivity (27°C) | 6.3 W/m·K |
| Electrical Properties | Metric |
| Electrical Resistivity | 1.22×10-4 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.