Yttrium (Y): Bohr Model, Protons, Neutrons & Electrons
Yttrium is element number 39, a transition metal in group 3, period 5. Its atom has 39 protons, 50 neutrons and 39 electrons arranged in 5 shells: 2, 8, 18, 9, 2.
Protons, neutrons and electrons in yttrium
The atomic number of yttrium is 39, so every yttrium atom has 39 protons. A neutral atom has the same number of electrons, 39. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For yttrium-89, that is 89 − 39 = 50 neutrons.
How to draw the Bohr model of yttrium
- Draw the nucleus and write 39 p⁺ and 50 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 9 electrons on it.
- Draw the fifth shell and put 2 electrons on it.
- Check: 2 + 8 + 18 + 9 + 2 = 39 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, 9, 2) is the one to draw.
Electron configuration
The electron configuration of yttrium is [Kr] 5s² 4d¹. As a transition metal it fills an inner d-subshell, and its common ion is Y³⁺.
Key facts about yttrium
| Symbol | Y |
|---|---|
| Atomic number | 39 |
| Relative atomic mass | 88.906 |
| Group · period · block | group 3 · period 5 · d-block |
| Type | Transition Metal |
| State at 25 °C | solid |
| Electron shells | 2, 8, 18, 9, 2 |
| Electron configuration | [Kr] 5s² 4d¹ |
| Valence electrons | varies (outer shell: 2) |
| Common ion | Y³⁺ |
| Electronegativity (Pauling) | 1.22 |
| First ionisation energy | 6.22 eV (600 kJ/mol) |
| Atomic radius (empirical) | 180 pm |
Where yttrium sits on the periodic table
Frequently asked questions
How many protons, neutrons and electrons does yttrium have?
Yttrium has 39 protons and 39 electrons (atomic number 39). Its most common isotope, yttrium-89, has 89 − 39 = 50 neutrons.
What is the electron configuration of yttrium?
[Kr] 5s² 4d¹. In shells that is 2, 8, 18, 9, 2.
How many valence electrons does yttrium have?
Yttrium is a transition metal, so its valence electrons are spread over two shells; its outermost shell holds 2.
Where is yttrium on the periodic table?
In group 3, period 5, in the d-block. It is a transition metal.
