Distinguish between the possibillities in complex ions of `Delta =0` and `CFSE =0` Give an example of each .

Explanation

To distinguish between the possibilities in complex ions of Δ = 0 and CFSE = 0, we need to understand the concepts of crystal field splitting energy (Δ) and crystal field stabilization energy (CFSE).

### Step-by-Step Solution:

1. **Understanding Δ = 0:**
- When Δ = 0, it indicates that there is no crystal field splitting occurring in the d-orbitals of the metal ion. This situation typically arises in gaseous ions where there is no interaction with ligands to cause splitting.
- **Example:** A good example of a complex ion where Δ = 0 is the gaseous ion of Zinc (Zn²⁺). In this case, there is no crystal field splitting because the ion is not surrounded by ligands.

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