\textbf{205-} The difference in lattice energy (enthalpy of crystallization) of which two compounds is less?
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(1) KF, LiCl \hspace{1cm} (2) LiBr, NaF \hspace{1cm} (3) LiF, NaCl \hspace{1cm} (4) $\text{Na}_2\text{O}$, $\text{MgF}_2$
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