Question

An example of an internal force for change is

Answer 1

U can take example of Vander wall forces in graphite...or any internal force acting on a particle..eg
when any liquid particle is heated the internal force between it becomes loose or get broken and acquires the structure of gas or vapour

Answer 2

The van der walls force can be considered as an internal force of change .

Explaination :

Any liquid if that is exposed to a lot of heat, then the internal force between the molecules of liquid gets lose and change takes place. The liquid then changes itself or it changes the form to gas or vapour.

Due to pressure, the internal force tightens or loosens and changes its form, at times, it may be liquid or liquid gasses or vapors .