WAEC Geography 2019 Papers

Concept:The crust is Earth's outer layer, composed of lighter silicate rocks than the denser mantle beneath it.Explanation:The continental crust is mostly granite, with an average density near $2.7\ \mathrm{g/cm^3}$.The oceanic crust is mostly basalt, slightly denser at about $2.9\ \mathrm{g/cm^3}$.Adding the variation in rock types gives the whole crust a density range from about $2.5\ \mathrm{g/cm^3}$ to $3.3\ \mathrm{g/cm^3}$.Answer:D. $2.5\ \mathrm{g/cm^3}$ to $3.3\ \mathrm{g/cm^3}$