Which one is not correct order of electro negativity.

Options

A. F `gt` Cl`gt` Br`gt` I
B. Si`gt` Al `gt` Mg`gt` Na
C. Cl`gt` S `gt` P `gt` Si
D. None of these

Answer

To determine which order of electronegativity is incorrect, we need to analyze the provided options based on the general trends in electronegativity across the periodic table.

### Step-by-Step Solution:

1. **Understanding Electronegativity**:
Electronegativity is the tendency of an atom to attract electrons in a chemical bond. It generally increases across a period (left to right) and decreases down a group (top to bottom).

2. **Analyzing the Options**:
- **Option A**: Fluorine (F) > Chlorine (Cl) > Bromine (Br) > Iodine (I)
- This order is correct. Electronegativity decreases as you move down the group.
- **Option B**: Sodium (Na) < Magnesium (Mg) < Aluminum (Al) < Silicon (Si)
- This order is also correct. Electronegativity increases as you move from left to right across a period.
- **Option C**: Chlorine (Cl) > Phosphorus (P) > Silicon (Si)
- This order is incorrect. Chlorine is indeed more electronegative than phosphorus, but silicon is less electronegative than phosphorus, making this order incorrect.

3. **Conclusion**:
Since Option C is the only incorrect order of electronegativity, the answer to the question is Option C.

### Final Answer:
The incorrect order of electronegativity is **Option C: Chlorine > Phosphorus > Silicon**.