The species `Ar,K^(+)` and `Ca^(2+)` contain the same number of electrons. In which order do their radii increase ?

Options

A. `Ca^(2+) lt Ar lt K^(+)`
B. `Ca^(2+) lt K^(+) lt Ar`
C. `K^(+) lt Ar lt Ca^(2+)`
D. `Ar lt k^(+) lt Ca^(2+)`

Answer

B

Explanation

In case of isoelectronic species the radius decrease with increase in nuclear charge

Ionic radius `prop 1/((Z//e))`