A student reported the radii of `Al ^(3+), Mg^(2+), and F ^(-)` as 136 pm, 65 pm and 50 pm respectively. Is the order correct ? Comment.

Explanation

To determine whether the reported radii of Al^(3+), Mg^(2+), and F^(-) are correct, we need to analyze the ionic sizes based on the number of protons and electrons in each ion.

### Step-by-Step Solution:

1. **Identify the ions and their electron configurations**:
- **Al^(3+)**: Aluminum has an atomic number of 13. When it loses 3 electrons to form Al^(3+), it has 10 electrons (13 - 3 = 10).
- **Mg^(2+)**: Magnesium has an atomic number of 12. When it loses 2 electrons to form Mg^(2+), it also has 10 electrons (12 - 2 = 10).
- **F^(-)**: Fluorine has an atomic number of 9. When it gains 1 electron to form F^(-), it has 10 electrons (9 + 1 = 10).
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