which element will form the ion with the largest ionic radius? f o n

Explanation:

Step1: Consider ion - formation and electron - configuration

These elements (N, O, F) form anions by gaining electrons. N gains 3 electrons to form $N^{3 -}$, O gains 2 electrons to form $O^{2 -}$, and F gains 1 electron to form $F^{-}$. All three ions have the same electron - configuration as neon (a noble gas configuration).

Step2: Apply the rule of ionic radius for isoelectronic species

For isoelectronic species (species with the same number of electrons), the ion with the smallest nuclear charge will have the largest ionic radius. The nuclear charge is determined by the number of protons. Nitrogen has 7 protons, oxygen has 8 protons, and fluorine has 9 protons.

Step3: Determine the ion with the largest radius

Since $N^{3 -}$ has the smallest nuclear charge among $N^{3 -}$, $O^{2 -}$, and $F^{-}$, it will have the largest ionic radius.

Answer:

N