Final answer:
The graduated cylinder with diamond will show a greater volume change when equal masses of diamond and platinum are submerged because diamond has a lower density than platinum and therefore a larger volume for the same mass.
Step-by-step explanation:
To determine which graduated cylinder would have the greatest volume change, we need to compare the density of diamond and platinum. Objects displace a volume of water equal to their own volume when submerged, and since we are considering equal masses, the substance with the lower density will have the larger volume and thus displace more water.
Diamond has a density of about 3.5 g/cm³, while platinum has a much higher density of approximately 21.4 g/cm³. Since the mass of the diamond and platinum is the same, the volume of the diamond will be greater because of its lower density. Therefore, when equal masses of diamond and platinum are submerged in water, the graduated cylinder with the diamond will show a greater volume change, as it displaces more water due to its larger volume.