The energy required to separate the ions in a CsF crystal lattice into individual Cs^+1 (g) and F^-1 (g) ions is known as the lattice energy of CsF(s). As shown in the table below, the lattice energy of CsF(s) is smaller than the lattice energy of a similar compound, KF(s). Which of the following best explains why the lattice energy of CsF is smaller than the lattice energy of KF? CsF = 759
KF = 829

A.) Cs^+ contains more core electrons than K4+, so the valence electrons in Cs^+ are more shielded from the nucleus than the valence electrons in K+.

B.) Cs^+ has a larger ionic radius than K^+, so the distance between cation and anion is greater in CsF than in KF.

C.) Cesium and fluorine have a greater electronegativity difference than potassium and fluorine, so the Cs-F bond is more polar than the K-F bond.

D.) Cesium has a smaller first ionization energy than potassium, so less energy is required to form the Cs^+ ion than to form the K^+ ion.