Which term describes the semi-liquid layer of the Earth's interior composed mainly of iron, silicon, and magnesium?

Which term describes the semi-liquid layer of the Earth's interior composed mainly of iron, silicon, and magnesium?

• A. Core
• B. Mantle
• C. Crust
• D. Atmosphere

Answer: (B)

Understanding Earth's internal layout and how each layer behaves is what this question hinges on. The semi-liquid layer is the mantle, which sits between the crust and the core. It’s made mainly of silicate minerals that contain magnesium and iron, with silicon as a key component. The temperatures and pressures here let rocks flow very slowly, especially in the upper part known as the asthenosphere, giving the mantle a partly molten, ductile character. This is different from the crust above, which is rigid and solid, and from the core below, which is mostly iron (the outer core is liquid and the inner core is solid). The atmosphere is a gaseous shell around the planet and isn’t part of the interior.

Understanding Earth's internal layout and how each layer behaves is what this question hinges on. The semi-liquid layer is the mantle, which sits between the crust and the core. It’s made mainly of silicate minerals that contain magnesium and iron, with silicon as a key component. The temperatures and pressures here let rocks flow very slowly, especially in the upper part known as the asthenosphere, giving the mantle a partly molten, ductile character. This is different from the crust above, which is rigid and solid, and from the core below, which is mostly iron (the outer core is liquid and the inner core is solid). The atmosphere is a gaseous shell around the planet and isn’t part of the interior.