What is the layer of molten iron and nickel that surrounds the inner core?

• A. Outer Core
• B. Inner Core
• C. Mantle
• D. Asthenosphere

Answer: (A)

The layer is the outer core. It surrounds the solid inner core and is made of liquid iron-nickel, which remains molten due to extremely high temperatures despite the immense pressures. This liquid metal moves in convection currents, powering Earth’s magnetic field. In contrast, the mantle and asthenosphere are silicate rocks, not molten iron-nickel, and the inner core is solid. Seismic evidence also shows the outer core’s liquid state because S-waves don’t travel through it, while P-waves refract and slow as they pass through.