# Which ion has the largest radius? "Na"^(+), "Ga"^(3+), "K"^(+), "Mg"^(2+), "Ca"^(2+)

Jun 18, 2018

$\text{K"^"+}$ has the largest radius.

#### Explanation:

The ionic radii of cations follow the same trends as atomic radii.

They increase from top to bottom and from right to left in the Periodic Table.

Thus, the ion with the largest radius is closest to the lower left corner of the Periodic Table, and that is the $\text{K"^"+}$ ion.