93Np237
Neptunium
Actinide · element 93 · f-block (shown below the main table)
Quick facts
| Symbol | Np |
|---|---|
| Atomic number | 93 |
| Relative atomic mass | 237 |
| Category | Actinide |
| Position | f-block (shown below the main table) |
| State at 20 °C | Solid |
| Melting point | 644 °C |
| Boiling point | — |
| Density | 20.45 g/cm³ |
| Electronegativity | 1.36 |
| Electron configuration | [Rn] 5f4 6d1 7s2 |
About Neptunium
Neptunium has the symbol Np and atomic number 93, which means every neptunium atom has 93 protons in its nucleus and, in a neutral atom, 93 electrons. At room temperature it is a solid.
Actinides are the second row of the f-block. They are all radioactive, and only a few (like uranium and thorium) occur naturally in large amounts.
It melts at 644 °C.
Explore it
See where neptunium sits, and drag the temperature slider to watch it melt and boil, on the interactive periodic table. Practise with quizzes on OmniEx.