The second ionisation enthalpies of both Cr and Cu are higher than those of the next element. Explain.

Explanation

To explain why the second ionization enthalpies of both chromium (Cr) and copper (Cu) are higher than those of their next elements (manganese (Mn) and zinc (Zn), respectively), we can analyze their electronic configurations and the stability associated with them.

### Step-by-Step Solution:

1. **Identify the Electronic Configurations**:
- Chromium (Cr) has the atomic number 24 and its electronic configuration is \( [Ar] 3d^5 4s^1 \).
- Manganese (Mn), the next element, has the atomic number 25 and its configuration is \( [Ar] 3d^5 4s^2 \).
- Copper (Cu) has the atomic number 29 and its configuration is \( [Ar] 3d^{10} 4s^1 \).
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