Answer:
atomic number 8 and atomic number 12
Explanation:
atomic number 8 and atomic number 12 , element with the atomic number 8 is oxygen, and the element with atomic number 12 is Magnesium
Magnesium has low ionization energy, hence higher tendency to loose its two outermost electrons to form positive ion.
Oxygen has high electron affinity, hence higher tendency to accept or gain electrons to form negative ion.
The electronegativity difference between the element with atomic number 8 and element with atomic number 12 is greater for the formation of ionic bond