Respuesta :
Your answer for the first question seems to be correct. The option B and O most likely to be part of a polyatomic ion. For question number two, your answer is also correct. They are the set of elements that will likely form poly atomic ions. For the last question , the correct answer is the option which has CN-.
Answer 1) The option B) Ba and O
Explanation : Barium and oxygen elements are the pairs which are most likely to be the part of polyatomic ion. As barium has +2 charge and Oxygen has -2 charge which will be settle once they form an polyatomic ion.
Answer 2) Oxygen and Carbon.
Explanation : Oxygen and carbon are the elements in nature which can combine with other elements and form a polyatomic ion. These are abundant in nature and can be easily form a polyatomic ion. Oxygenated and Carbonated polyatomic ions are found to be the most stable ions.
Answer 3) Option B) [tex] CN^{-} [/tex]
Explanation : The anion which contains the oxygen atom in its molecular formula can be called as oxyanion. In the given options [tex] CN^{-} [/tex] is the only option where there is no oxygen atom present in the molecular formula. Hence, [tex] CN^{-} [/tex] is the correct option.