Which statement best describes the Earth's core composition?

Which statement best describes the Earth's core composition?

• A. It is made of water and rock
• B. It is a gas sphere
• C. It is composed of molten metal
• D. It is entirely solid iron

Answer: (C)

The main idea being tested is what the Earth's core is made of and its physical state. The core is primarily metallic iron with some nickel. The outer part is molten, which allows convection of liquid iron and helps drive Earth's magnetic field, while the inner part remains solid under immense pressures. This is why describing the core as composed of molten metal best fits what we know: it emphasizes both the metallic composition and the molten state of the outer core, which is a key feature, even though the inner core is solid. The other descriptions don't match what the core actually contains or its state: water and rock pertain to the crust and mantle, a gas sphere would describe a gas giant, and saying it is entirely solid iron ignores the liquid outer core.

The main idea being tested is what the Earth's core is made of and its physical state. The core is primarily metallic iron with some nickel. The outer part is molten, which allows convection of liquid iron and helps drive Earth's magnetic field, while the inner part remains solid under immense pressures.

This is why describing the core as composed of molten metal best fits what we know: it emphasizes both the metallic composition and the molten state of the outer core, which is a key feature, even though the inner core is solid. The other descriptions don't match what the core actually contains or its state: water and rock pertain to the crust and mantle, a gas sphere would describe a gas giant, and saying it is entirely solid iron ignores the liquid outer core.