# The ionic radius of

Question:

The ionic radius of $\mathrm{Na}^{+}$ions is $1.02 \backslash \mathrm{AA}$. The ionic radii (in $\backslash \mathrm{AA}$ ) of $\mathrm{Mg}^{2+}$ and $\mathrm{Al}^{3+}$, respectively, are

1. $1.05$ and $0.99$

2. $0.72$ and $0.54$

3. $0.85$ and $0.99$

4. $0.68$ and $0.72$

Correct Option: , 2

Solution:

The ionic radii order is $\mathrm{Na}^{+}>\mathrm{Mg}^{2+}>\mathrm{Al}^{3+}$