# Orbitals

> The five orbitals of the d sublevel


## Objectives

- Describe an orbital as a region around the nucleus where the electron is most likely to be found, not a circular path.
- State the number of orbitals in s, p, d and f: 1, 3, 5 and 7.
- Use 'at most two electrons per orbital' to find the maximum electrons in a sublevel.

## 1. Orbitals: from zero




## 2. Why five?

How many orbitals does the d sublevel have?

- 10
- 2
- 5 ✓

The d sublevel holds up to 10 electrons, and one orbital holds at most 2. So d has 10 ÷ 2 = 5 orbitals.

[ar-EG] الـ d sublevel بيشيل لحد 10 electrons، والـ orbital الواحد بيشيل 2 بالكتير. يبقى الـ d فيه 10 ÷ 2 = 5 orbitals.
## 3. An orbital is a region, not a path

Orbital The region of space around the nucleus in which the electron is most likely to be found. An s orbital. The dots show where the electron is likely to be: the denser, the more likely. An orbital is a circular path (orbit) that the electron follows around the nucleus.


## 4. Orbitals in each sublevel

Each box is one orbital. Each orbital holds at most 2 electrons. Full sublevels: s has 1 orbital (2 electrons), p has 3 (6), d has 5 (10)


## 5. Count the orbitals

The f sublevel holds up to 14 electrons. How many orbitals does it have?

- 28
- 14
- 7 ✓
- 4

The f sublevel holds up to 14 electrons, 2 per orbital, so it has 14 ÷ 2 = 7 orbitals.

[ar-EG] الـ f sublevel بيشيل لحد 14 electrons، 2 في الـ orbital الواحد، يبقى فيه 14 ÷ 2 = 7 orbitals.
## 6. Summary

An orbital is a region where the electron is most likely to be found, not a path. Orbitals: s 1, p 3, d 5, f 7. At most 2 electrons per orbital, so d holds 5 × 2 = 10. Back to the hook Ch.1 p.8: the **five orbitals** of the (3d) sublevel are filled gradually, one electron in each orbital first (Hund's rule). Can you explain why the 3d sublevel can hold 10 electrons? A full 3d sublevel: 5 orbitals, 2 electrons each The 3d sublevel has 5 orbitals, and each orbital holds at most 2 electrons: 5 × 2 = 10.



Chapter: Transition Elements (https://yaani.ai/ar/learn/chemistry/chem-s3-en.ch1)
Source: https://yaani.ai/ar/lesson/chem-s3-en.lesson-atom.orbitals