Earth's layers can be distinguished by density and what other property? shape composition mass

Composition

Explanation:

Earth's layers can be distinguished by both the property of both density and composition. The earth is comprised of 3 different layers whose density and composition significantly changes with depth. The density of the crust is the lowest and the density of the core is the highest. The composition and density of different layers of the earth's interior are as follows-

(1) Core- it is comprised of hot molten materials that include the alloys of Iron (Fe) and Nickel (Ni) and other siderophile elements. The average density of this layer is about 12.5 g/cm³.

(2) Mantle- This layer is comprised of rocks that primarily contain Silicon (Si), Magnesium (Mg), Iron (Fe), Oxygen (O), Aluminum (Al), in association with some other minerals. The average density of this layer is 4.5 g/cm³.

(3) Crust- This is the outermost hard layer that is made up of rocks containing Oxygen (O),  Aluminum (Al), Potassium (K), Iron (Fe), Calcium (Ca), Silicon (Si), Sodium (Na) and some amount of Magnesium (Mg). The continental crust is comprised of granitic composition whereas the oceanic crust is comprised of basaltic composition. The average density of the crust is approximately 2.5 g/cm³.

Thus, both density and composition are two distinguishable properties.

i think it's letter a.