Using the data in Table 9-1, compute the net energy required to transfer an electron between the following pairs of atoms: Cs to F, Li to I, and Rb to Br.

Table 9-1 Ionization energies of alkali metal atoms and electron affinities of halogen atoms Ionization energy (eV) Halogen Electron affinity (eV) Alkali metal Li Na K Rb Cs Fr 5.39 5.14 4.34 4.18 3.89 4.07 F C1 Br I At 3.40 3.62 3.36 3.06 2.8