Elements / 93
93Np[237]
Neptunium
Actinide · f-block · ring Q
Neptunium is element 93, an actinide. It is one of the actinides, which the spiral keeps in line on ring Q instead of exiling them to a strip below the table.
Properties
| Density | 20.4 g/cm³5th densest of 99 | Terrain → |
|---|---|---|
| Melting point | 912 K · 639 °C | Terrain → |
| Boiling point | 4,447 K · 4,174 °C | Terrain → |
| Electronegativity | 1.36 | Terrain → |
| First ionization energy | 605 kJ/mol | Terrain → |
| Atomic weight | 237 u | Terrain → |
| Crustal abundance | Not measured | Terrain → |
| Discovered | 1940 | Terrain → |
Values from open reference data; see sources. "Terrain" opens that property as a 3D landscape across the whole spiral.
Two things you might not know
- Enrico Fermi once proposed calling it ausenium, after Ausonia, the Greek name for Italy.
- Named after the planet beyond Uranus. Made by McMillan and Abelson at Berkeley in 1940, the first element past uranium.
Checked against en.wikipedia.org.
Actinides
- Ac Actinium
- Th Thorium
- Pa Protactinium
- U Uranium
- Np Neptunium
- Pu Plutonium
- Am Americium
- Cm Curium
- Bk Berkelium
- Cf Californium
- Es Einsteinium
- Fm Fermium
- Md Mendelevium
- No Nobelium
Ring Q (period 7)
Play with Neptunium
Watch it fly into its seat, or raise the whole spiral into a landscape and see where it peaks.