Question

which ion is bigger and why among Na+, Al-3,Mg+2,F-,O-2,N-3​

Answer 1

Answer:

Here $N^{-3$ is the biggest ion

We see in this series that all the elements have 10 electrons, thus are Isoelectronic species. Now, more the number of protons in their nucleus more is the nuclear pull and hence less is the atomic size. Hence, more the atomic number, more is the number of electrons hence less is the atomic size.

The list thus stands as:

N³‐ > O²- > F- > Na+ > Mg²+ > Al³+