Which one of the following ions has the highest value of ionic radius?

Options

A. `O^(2-)`
B. `B^(3+)`
C. `Li^(+)`
D. `F^(-)`

Answer

A

Explanation

`O^(--)` and `F^(-)` are isoelectronic. Hence have same number of shells, therefore greater the nuclear charge smaller will be the size i.e.,
`O^(--)gtF^(-)`
Further `Li^(+)` and `B^(3+)` are isoelectronic. Therefore
`LigtB^(3+)`
Hence the correct order of atomic size is.
`O^(--)gtF^(-)gtLi^(+)gtB^(3+)`