How does the lattice energy for an ionic solid relate to the size of the ions in the ionic solid? Lattice energy becomes more exothermic (more negative) with increasing ionic radius. Lattice energy becomes less exothermic (less negative) with decreasing ionic radius. Lattice energy is unrelated to the size of the ions. Lattice energy becomes less exothermic (less negative) with increasing ionic radius. How does the lattice energy for an ionic solid relate to the magnitude of the charge of the ions in the ionic solid? Lattice energy becomes more exothermic (more negative) with decreasing magnitude of ionic charge. Lattice energy is unrealted to the charge of the ions. Lattice energy becomes less exothermic (less negative) with increasing magnitude of ionic charge. Lattice energy becomes more exothermic (more negative) with increasing magnitude of ionic charge.