Dubnio (Db): Bohr Model, Protons, Neutrons & Electrons
Dubnio is element number 105, a superheavy in group 5, period 7. Its atom has 105 protons, 163 neutrons and 105 electrons arranged in 7 shells: 2, 8, 18, 32, 32, 11, 2.
- 105 protons
- 163 neutrons
- 105 electrons
Protons, neutrons and electrons in dubnium
El atomic number of dubnium is 105, so every dubnium atom has 105 protons. A neutral atom has the same number of electrons, 105. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For dubnium-268, that is 268 − 105 = 163 neutrons. Every isotope of dubnium is radioactive; 268 is the mass number of its most stable one.
How to draw the Bohr model of dubnium
- Draw the nucleus and write 105 p⁺ y 163 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 32 electrons on it.
- Draw the sixth shell and put 11 electrons on it.
- Draw the seventh shell and put 2 electrons on it.
- Check: 2 + 8 + 18 + 32 + 32 + 11 + 2 = 105 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, 32, 11, 2) is the one to draw.
Electron configuration
The electron configuration of dubnium is [Rn] 7s² 5f¹⁴ 6d³. As a superheavy it fills an inner d-subshell, and its common ion is variable.
Key facts about dubnium
| Symbol | Db |
|---|---|
| Atomic number | 105 |
| Relative atomic mass | [268] |
| Group · period · block | group 5 · period 7 · d-block |
| Tipo | Sobrepesado |
| State at 25 °C | unknown |
| Capas electrónicas | 2, 8, 18, 32, 32, 11, 2 |
| Electron configuration | [Rn] 7s² 5f¹⁴ 6d³ |
| Electrones de valencia | varies (outer shell: 2) |
| Common ion | — |
| Electronegativity (Pauling) | — |
| First ionisation energy | — |
| Atomic radius (empirical) | — |
¿Dónde dubnium sits on the periodic table
Preguntas frecuentes
How many protons, neutrons and electrons does dubnium have?
Dubnium has 105 protons and 105 electrons (atomic number 105). Its most common isotope, dubnium-268, has 268 − 105 = 163 neutrons.
What is the electron configuration of dubnium?
[Rn] 7s² 5f¹⁴ 6d³. In shells that is 2, 8, 18, 32, 32, 11, 2.
How many valence electrons does dubnium have?
Dubnium is a superheavy, so its valence electrons are spread over two shells; its outermost shell holds 2.
Where is dubnium on the periodic table?
In group 5, period 7, in the d-block. It is a superheavy.
