Dysprosium (Dy): Bohr Model, Protons, Neutrons & Electrons
Dysprosium is element number 66, a lanthanide in the f-block (the lanthanide row drawn below the table), period 6. Its atom has 66 protons, 98 neutrons and 66 electrons arranged in 6 shells: 2, 8, 18, 28, 8, 2.
Protons, neutrons and electrons in dysprosium
The atomic number of dysprosium is 66, so every dysprosium atom has 66 protons. A neutral atom has the same number of electrons, 66. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For dysprosium-164, that is 164 − 66 = 98 neutrons. Dysprosium has 7 stable isotopes, with 90, 92, 94, 95, 96, 97, 98 neutrons.
How to draw the Bohr model of dysprosium
- Draw the nucleus and write 66 p⁺ and 98 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 28 electrons on it.
- Draw the fifth shell and put 8 electrons on it.
- Draw the sixth shell and put 2 electrons on it.
- Check: 2 + 8 + 18 + 28 + 8 + 2 = 66 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, 28, 8, 2) is the one to draw.
Electron configuration
The electron configuration of dysprosium is [Xe] 6s² 4f¹⁰. As a lanthanide it fills an inner f-subshell, and its common ion is Dy³⁺.
Key facts about dysprosium
| Symbol | Dy |
|---|---|
| Atomic number | 66 |
| Relative atomic mass | 162.5 |
| Group · period · block | f-block · period 6 |
| Type | Lanthanide |
| State at 25 °C | solid |
| Electron shells | 2, 8, 18, 28, 8, 2 |
| Electron configuration | [Xe] 6s² 4f¹⁰ |
| Valence electrons | varies (outer shell: 2) |
| Common ion | Dy³⁺ |
| Electronegativity (Pauling) | 1.22 |
| First ionisation energy | 5.94 eV (573 kJ/mol) |
| Atomic radius (empirical) | 175 pm |
Where dysprosium sits on the periodic table
Frequently asked questions
How many protons, neutrons and electrons does dysprosium have?
Dysprosium has 66 protons and 66 electrons (atomic number 66). Its most common isotope, dysprosium-164, has 164 − 66 = 98 neutrons.
What is the electron configuration of dysprosium?
[Xe] 6s² 4f¹⁰. In shells that is 2, 8, 18, 28, 8, 2.
How many valence electrons does dysprosium have?
Dysprosium is a lanthanide, so its valence electrons are spread over two shells; its outermost shell holds 2.
Where is dysprosium on the periodic table?
In the f-block (the lanthanide row drawn below the table), period 6, in the f-block. It is a lanthanide.
