Stretching of a rubber a physical change because the streching doesn't change the chemical composition of rubber. rubber are made up of cross-linked polymer,long-chain molecules connected to each other that initially exist in a collide state . stretching
these chains in order to lengthen and align them in the direction of the applied force , we see that no chemical change has happened because if we will leave it we will see tht it comes back to his original shape. so it is concluded that streching of rubber is a physical change .
i hope it will be helpful to u . pls giv it as a best answer if u like the ans