Neptunio (Np): Bohr Model, Protons, Neutrons & Electrons
Neptunio is element number 93, an actinide in the f-block (the actinide row drawn below the table), period 7. Its atom has 93 protons, 144 neutrons and 93 electrons arranged in 7 shells: 2, 8, 18, 32, 22, 9, 2.
- 93 protons
- 144 neutrons
- 93 electrons
Protons, neutrons and electrons in neptunium
El atomic number of neptunium is 93, so every neptunium atom has 93 protons. A neutral atom has the same number of electrons, 93. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For neptunium-237, that is 237 − 93 = 144 neutrons. Every isotope of neptunium is radioactive; 237 is the mass number of its most stable one.
How to draw the Bohr model of neptunium
- Draw the nucleus and write 93 p⁺ y 144 n⁰ inside it.
- Draw the first shell and put 2 electrons on it (the first shell holds at most 2).
- Draw the second shell and put 8 electrons on it.
- Draw the third shell and put 18 electrons on it.
- Draw the fourth shell and put 32 electrons on it.
- Draw the fifth shell and put 22 electrons on it.
- Draw the sixth shell and put 9 electrons on it.
- Draw the seventh shell and put 2 electrons on it.
- Check: 2 + 8 + 18 + 32 + 22 + 9 + 2 = 93 electrons, the same as the number of protons.
From potassium onwards the shells don’t simply fill as 2, 8, 8: the fourth shell starts before the third is full, so the real arrangement above (2, 8, 18, 32, 22, 9, 2) is the one to draw.
Electron configuration
The electron configuration of neptunium is [Rn] 7s² 5f⁴ 6d¹. As an actinide it fills an inner f-subshell, and its common ion is Np³⁺.
Key facts about neptunium
| Symbol | Np |
|---|---|
| Atomic number | 93 |
| Relative atomic mass | [237] |
| Group · period · block | f-block · period 7 |
| Tipo | Actínido |
| State at 25 °C | solid |
| Capas electrónicas | 2, 8, 18, 32, 22, 9, 2 |
| Electron configuration | [Rn] 7s² 5f⁴ 6d¹ |
| Electrones de valencia | varies (outer shell: 2) |
| Common ion | Np³⁺ |
| Electronegativity (Pauling) | 1.36 |
| First ionisation energy | 6.27 eV (605 kJ/mol) |
| Atomic radius (empirical) | 175 pm |
¿Dónde neptunium sits on the periodic table
Preguntas frecuentes
How many protons, neutrons and electrons does neptunium have?
Neptunium has 93 protons and 93 electrons (atomic number 93). Its most common isotope, neptunium-237, has 237 − 93 = 144 neutrons.
What is the electron configuration of neptunium?
[Rn] 7s² 5f⁴ 6d¹. In shells that is 2, 8, 18, 32, 22, 9, 2.
How many valence electrons does neptunium have?
Neptunium is an actinide, so its valence electrons are spread over two shells; its outermost shell holds 2.
Where is neptunium on the periodic table?
In the f-block (the actinide row drawn below the table), period 7, in the f-block. It is an actinide.
