J.R. S. answered 11/21/17
Ph.D. University Professor with 10+ years Tutoring Experience
More exothermic means that more energy is LIBERATED, not that more energy needs to be added. And, in general, ionic bonds are considerably stronger than covalent bonds. Look at the properties of ionic vs. covalent compounds, and this becomes evident (melting point, hardness, etc). Does this help answer your question?