Name: Neptunium
Symbol: Np
Atomic Number: 93
Atomic Mass: (237.0) amu
Melting Point: 640.0 °C (913.15 °K, 1184.0 °F)
Boiling Point: 3902.0 °C (4175.15 °K, 7055.6 °F)
Number of Protons/Electrons: 93
Number of Neutrons: 144
Crystal Structure: Orthorhombic
Density @ 293 K: 20.45 g/cm3
Color: Unknown
Atomic Structure
![[Bohr Model of Neptunium]](b0093.gif) |
Number of Energy Levels: 7 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 32 Fifth Energy Level: 23 Sixth Energy Level: 8 Seventh Energy Level: 2 |
Isotopes
| Isotope | Half Life |
| Np-235 | 1.08 years |
| Np-236 | 155000.0 years |
| Np-236m | 22.5 hours |
| Np-237 | 2140000.0 years |
| Np-238 | 2.11 days |
| Np-239 | 2.35 days |
| Np-240 | 1.03 hours |
| Np-240m | 7.22 minutes |
Facts
Date of Discovery: 1940Discoverer: E.M. McMillan
Name Origin: After the planet Neptune
Uses: No uses known
Obtained From: Man-made
Information provided by: http://www.chemicalelements.com