Question

The lower mantle has an average density of 5.5 grams per cubic centimeter. Which of the following could be the density of the outer core?

A.3.5 grams per cubic centimeter
B.5.5 grams per cubic centimeter
C.10.0 grams per cubic centimeter

Answer 1

Option (C)

Step-by-step explanation:

The earth is divided into three layers namely-

1. Crust
2. Mantle (upper and lower mantle)
3. Core (inner core and outer core)

This three layers are different from one another in terms of density and physical characteristics. The density of the crust is about 2.5 g/cm³. The density of the upper mantle and the lower mantle are about 3.6 g/cm³ and 5.5 g/cm³ respectively. And lastly, the density of outer core and inner core are approximately 10 g/cm³ and 13 g/cm³.

Thus, according to the given question, the density of outer core (10 g/cm³) is more than the lower mantle (5.5 g/cm³), because the core is rich in denser materials such as iron, sulfur and nickel, which are liquid in nature in the outer core and solid in nature in the inner core.

Hence, the correct answer is option (C).

Answer 2

A. 3.5 grams per cubic centimeter is the density of the outer core because it floats.