Plot the stress versus strain curve for rubber and what does the area of the loop of the curve represent?
When the rubber undergoes the cycle of loading and unloading some of the mechanical energy is lost in the cycle. The area under the graph is equal to the work done to complete the cycle of loading and unloading. The below graph is a hysteresis curve.
What do you understand by intermolecular forces?
Intermolecular force is the force between the molecules of the substance is called intermolecular force.
There is a dipole-dipole interaction between the molecules.
Adhesive force is the attractive force between two unlike molecules. They are caused by forces acting between two substances like electrostatic force (attraction due to opposing charges), mechanical force etc.