Question

The order of magnitude of ionic radii of ions `Na^(+),Mh^(2+),Al^(3+)` and `Si^(4+)` is
A. `Na^(+) lt Mg^(2+) lt Al^(3+) lt Si^(4+)`
B. `Mg^(2+) gt Na^(+) gt Al^(3+) gt Si^(4+)`
C. `Al^(3+) gt Na^(+) gt Si^(4+) gt Mg^(2+)`
D. `Na^(+) gt Mg^(2+) gt Al^(3+) gt Si^(4+)`

Answer 1

Correct Answer - D
`Na^(+) gt Mg^(2+) gt Al^(3+) gt Si^(4+)` . All the isoelectronic but nuclear charge per electorn is greatest for `Si^(4+)`. So it has smallest size and nuclear charge per electron for `Na^(+)` is smallest. So it has largest size.