What is the nature of chemical bonding between $Cs$ and $F$?

Which of the following is a favourable condition for the formation of an ionic bond?

Element $x$ is strongly electropositive and $y$ is strongly electronegative. Both elements are univalent. The compound formed from their combination will be:

The pair in which the first compound is ionic and the second compound is covalent,is

The electronic configurations of elements are $A = 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2$ and $B = 1s^2 2s^2 2p^6 3s^2 3p^5$. Which of the following is the formula of the ionic compound that could be formed between these two elements $A$ and $B$?

Which of the following compounds contains an electrovalent (ionic) bond?