Final answer:
The element of art that defines the amount of space occupied by an object is b. volume, which applies to 3-dimensional work. Density describes the mass per unit volume, which can explain why objects of the same mass can have different volumes.
Step-by-step explanation:
The element of art that defines the amount of space occupied by an object is b. volume. Volume usually applies to 3-dimensional work and denotes the amount of space an object contains. A sculpture, for instance, has a volume that we can perceive by the space it occupies. This can include the interior space of a hollow object or vessel.
In contrast, mass in artwork suggests weight, density, and bulk, reflecting how the volume and density of the object give it a perceived heaviness, like in architecture where the resistance of gravity is a key consideration.
When we talk about density, it's described as how much mass exists per unit volume. This directly relates to why two objects with the same mass can have vastly different volumes due to their density. An example would be comparing a penny to an inflated balloon; both may have the same mass but due to differences in density, they have significantly different volumes.