Two atoms in a molecule are separated by a distance r. The potential energy between these two particular atoms depends on the separation of the atoms and is shown below as a function of the distance between the atoms (on some arbitrary scale). Note: a realistic potential function would have only one well. (a) At what distance(s) is there no force of one atom on the other? (b) Suppose the atoms are separated by the distance shown in point A on the graph. What happens if they are moved apart slightly? What about if they are moved together slightly? (c) How does your answer change if they start at position B or C? (d) What is the meaning of the word "equilibrium"? Think about what you've concluded in parts A – C and determine the positions of "stable" and "unstable" equilibrium (e) Why is a chemical bond similar to a spring? - U(r) B

Two atoms in a molecule are separated by a distance r. The potential energy between these two particular atoms depends on the separation of the atoms and is shown below as a function of the distance between the atoms (on some arbitrary scale). Note: a realistic potential function would have only one well. (a) At what distance(s) is there no force of one atom on the other? (b) Suppose the atoms are separated by the distance shown in point A on the graph. What happens if they are moved apart slightly? What about if they are moved together slightly? (c) How does your answer change if they start at position B or C? (d) What is the meaning of the word "equilibrium"? Think about what you've concluded in parts A – C and determine the positions of "stable" and "unstable" equilibrium (e) Why is a chemical bond similar to a spring? - U(r) B