Which elements are not likely to be formed in the sun sometime during its life cycle?

correct answer is iron

Explanation:

solution

as Iron is only formed in the cores of the star that is more massive than the sun because it takes very much energy  as gravitational force push inward on the star  

and the sun can form the helium and  carbon and the oxygen and also other elements  

but not the iron or any iron group element

so correct answer is iron

a.   mass number from atomic number