1. Electronic Configuration:
* Full configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵
* Condensed configuration: [Ar] 4s¹ 3d⁵
2. Understanding the Aufbau Principle and Hund's Rule:
* Aufbau Principle: Electrons fill orbitals in order of increasing energy levels.
* Hund's Rule: Electrons will individually occupy each orbital within a subshell before doubling up in any one orbital.
3. Orbital Diagram:
* 4s: This orbital has a single electron, represented as an up arrow (↑).
* 3d: This subshell has five orbitals (dxy, dyz, dxz, dx²-y², dz²), each capable of holding two electrons. According to Hund's Rule, each of the five 3d orbitals will get one electron before any pairing occurs.
Orbital Diagram for Cr:
```
↑ ↑ ↑ ↑ ↑
_ _ _ _ _
4s | | | | |
_ _ _ _ _
3d | ↑ | ↑ | ↑ | ↑ | ↑ |
_ _ _ _ _
```
Explanation:
* Chromium's Exception: You might notice that the expected configuration would be [Ar] 4s² 3d⁴. However, Chromium has a half-filled 3d subshell, which is more stable than having a filled 4s orbital and a partially filled 3d subshell. This is due to the added stability of having a half-filled subshell.
Let me know if you have any further questions!
