Which of the following species has the largest radius?

The element expected to form the largest ion to achieve the nearest noble gas configuration is

The statement$(s)$ that are correct about the species $O^{2-}$,$F^{-}$,$Na^{+}$,and $Mg^{2+}$.
$(A)$ All are isoelectronic
$(B)$ All have the same nuclear charge
$(C)$ $O^{2-}$ has the largest ionic radii
$(D)$ $Mg^{2+}$ has the smallest ionic radii
Choose the most appropriate answer from the options given below :

Describe the theory associated with the radius of an atom as it:
$(a)$ gains an electron
$(b)$ loses an electron

Which of the following is the correct order of the ionic radii of the given ions?

The atomic radii in the periodic table among elements from right to left: