Francium is an unstable element, and only some theoretical data are available for it. Estimate the lattice energy of francium chloride, FrCl(s). Enter your numeric answer including the correct sign in the units of kJ/mol. Enter the value only, do not enter the unit. Available data: Bond energy of Cl2: 245 kJ/mol lonization energy of Francium: 292 kJ/mol Electron affinity of Cl: -340 kJ/mol Standard enthalpy of formation of FrCl: -397 kJ/mol Enthalpy of sublimation of francium Fr(s): 58 kJ/mol