Final answer:
The energy change when bromine absorbs an electron is approximately -6.43 kJ.
Step-by-step explanation:
The energy change when bromine absorbs an electron can be determined using the enthalpy of vaporization (ΔHvap) of bromine. The ΔHvap of Br2 is 15.4 kJ/mol, which can be used as a conversion factor to determine the energy change when 1 mole of Br2 absorbs an electron. Since the process is exothermic, the energy change will be negative. Thus, the energy change when bromine absorbs an electron is approximately -6.43 kJ.