Which layer is described as the central, metallic sphere of the Earth?

Which layer is described as the central, metallic sphere of the Earth?

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

Answer: (C)

The central, metallic sphere refers to Earth's core. The core sits at the planet’s center and is made mainly of iron and nickel, giving it a very dense, metallic nature. It’s divided into a solid inner core and a surrounding liquid outer core. Above it lie the rocky mantle and crust, and encasing all of that is the atmosphere, the gaseous layer. This makes the core the distinct central layer described as metallic, unlike the surrounding rocky layers or the atmospheric envelope. Seismic data show changes in how waves travel at different depths, which helps scientists identify these distinct layers and confirms that the dense, metallic core lies at the center.