Arrange the following isoelectronic species `(O^(2-) , F^(-) , Na^+, Mg^(2+))` in order of:
increasing ionic radius

Explanation

To arrange the isoelectronic species \( O^{2-}, F^{-}, Na^{+}, Mg^{2+} \) in order of increasing ionic radius, we can follow these steps:

### Step 1: Identify the number of electrons
All the given species are isoelectronic, meaning they have the same number of electrons. In this case, all species have 10 electrons:
- \( O^{2-} \) has gained 2 electrons (8 protons + 2 electrons = 10 electrons).
- \( F^{-} \) has gained 1 electron (9 protons + 1 electron = 10 electrons).
- \( Na^{+} \) has lost 1 electron (11 protons - 1 electron = 10 electrons).
- \( Mg^{2+} \) has lost 2 electrons (12 protons - 2 electrons = 10 electrons).
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