Two objects of the same size will not have the same mass.
Step-by-step explanation:
Mass is the amount of the matter present in an object.
If the size and shape differs then the mass in that object will also differ.
For example, if we take 2 balls of the same size namely one plastic ball and other one rubber ball.
Both the balls are of same size, but the mass present in plastic ball is lesser when compared to the rubber ball.
So rubber ball has more mass than the plastic ball, and so it is concluded that two objects of the same size will not always have the same mass.