Answer
Ag$^{+}$ and Sn$^{4+}$
F$^{-}$ and N$^{3-}$
V and Fe$^{3+}$
Ar and P$^{3-}$
Work Step by Step
Since the number of electrons in a neutral atom is the same as the number of atoms, one can use a periodic table to count back and forth when electrons are added or taken away from an ion. For example, when one electron is taken away from silver in Ag$^{+}$, there are 46 electrons, which is the same as when 4 electrons are taken away from tin, in Sn$^{4+}$.
