The compound in which the cation is isoelectronic with the anion is

Which of the following statements is correct for $CsBr_3$?

In the crystals of which of the following ionic compounds would you expect maximum distance between the centres of cations and anions?

The ionic bonds $X^{+}Y^{-}$ are formed when
$I$. electron affinity of $Y$ is high
$II$. ionization energy of $X$ is low
$III$. lattice energy of $XY$ is high
$IV$. lattice energy of $XY$ is low
Choose the correct code.

The strongest ionic bond is present in:

The electronic configurations of four elements $L$,$P$,$Q$,and $R$ are given as: $L (1s^2, 2s^2 2p^4)$; $Q (1s^2, 2s^2 2p^6, 3s^2 3p^5)$; $P (1s^2, 2s^2 2p^6, 3s^1)$; $R (1s^2, 2s^2 2p^6, 3s^2)$. The formulas of the ionic compounds that can be formed between these elements are: