Which of these pairs of elements is most likely to be part of a polyatomic ion? k and f li and i mg and br s and o

Option (d) is the correct answer.

Explanation:

A polyatomic ion is defined as the ion formed by two or more number of atoms which actually covalently combine together.

This means that only non-metals combine covalently together as a covalent bond is formed by sharing of electrons.

For example, S and O atoms are covalent and they tend to form polyatomic ions when combine together.

Whereas K and F, Li and I, Mg and Br are all metals and non-metals. So, they will always form an ionic bond as the metal will transfer its valence electrons to the non-metal.

Thus, we can conclude that out of the given options S and O pairs of elements is most likely to be part of a polyatomic ion.