The fluid filled area between the pleural layers is called the pleural cavity.
Density (p) is defined as the mass (m) per unit volume (v) or:
p = m/v
Using this relationship, the volume is:
v = m/p
Using the given values of mass of 80 grams and density of 8 g/cm3, the sample volume is:
v = 80 grams/8 grams/cm3
v = 10 cm3
The final answer is 10 cm3.
The definition/term for matter that is a substance made of different kinds of atoms bonded together is a compound. That definition is for the word compound. Hope I helped!