Explain why the lattice energy of CaSe is approximately 4 times as large as that of KBr. Check all that apply. Check all that apply. According to Coulomb’s law, the Ca and Se ions have 4 times the attractive force (2+ × 2-) than that of the K and Br ions (1+ × 1-). According to Coulomb’s law, the Ca and Se ions have 4 times the repulsive force (2+ × 2-) than that of the K and Br ions (1+ × 1-). The lattice energy depends only on the sizes of constituent ions of the compound. The Ca2+ and K+ ions are four times larger in size than the Se2- and Br- ions. They Ca2+ and K+ ions are similar in size, as are the Se2- and Br- ions. Thus, the major difference in the lattice energies for these two compounds is due to the difference in the magnitude of the ionic charge on each ion. The lattice energy depends on the sizes of constituent ions of the compound. The Ca2+ is four times larger in size than the Se2- ion.