`Na^(+), Mg^(2+), Al^(3+)`, and `Si^(4+)` are isoelectronic ions. Their ionic size will follow the order

Options

A. `Na^(+) gt Mg^(2+) gt Al^(3+) gt Si^(4+)`
B. `Na^(+) lt Mg^(2+) lt Al^(3+) lt Si^(4+)`
C. `Na^(+) gt Mg^(2+) gt Al^(3+) lt Si^(4+)`
D. `Na^(+) lt Mg^(2+) gt Al^(3+) lt Si^(4+)`

Answer

A

Explanation

`{:("Species",Na^(+),Mg^(2+),Al^(3+),Si^(4+)),("Protons",11,12,13,14),("Electrons",10,10,10,10):}`
Size of isoelectronic cations decreases with increase in magnitude of nuclear charge
`:.` Order of decreasing size is
`Na^(+) gt Mg^(2+) gt Al^(3+) gt Si^(4+)`