1. The problem statement, all variables and given/known data I don't actually need help with an entire problem, I just can't seem to figure out what goes on when an atom is formed from a molecule in a Born-Haber cycle. For example: The formation of a chlorine atom from a chlorine molecule (1/2)Cl2 → Cl(g) ΔH = (1/2) x bond energy of Cl2 = +122 kJ 2. Relevant equations 3. The attempt at a solution Why is the bond energy being halved? It you have a Cl2 molecule, and you need 244 kJ to break the bond into two Cl atoms. Why would the formation of a Cl atom be only half of that then?