Answer
The distance of the Cl-Cl bond at the minimum on the graph is the actual Cl-Cl bond length.
Work Step by Step
At the minimum for the graph, the repulsive and attractive forces between the two Chlorine atoms are balanced. Because the attractive and repulsive forces are balanced, this is the most stable bond length for a Cl-Cl bond, so it is the natural length of a Cl-Cl bond.
