Step-by-step explanation:
Since, density is the amount of mass present in volume of the substance.
Hence, Density =
So, more is the mass of a substance more will be its density. Whereas more is the volume occupied by a substance less will be its density.
This also means that when more matter is present within a substance then it will have more mass. As a result, the substance will have more density.
Thus, we can conclude that golf ball has less mass than a tennis ball because it contains less matter.