Science Olympiad Dynamic Planet Practice Test

What describes the outer core of the Earth?

1. A layer of solid rock

2. A layer of molten iron and nickel

3. A layer of dense granite

4. A layer of liquid water

The correct answer is: A layer of molten iron and nickel

The outer core of the Earth is described as a layer of molten iron and nickel. This is based on extensive geological studies and seismic data, which indicate that the outer core is in a liquid state due to the extremely high temperatures and pressures found at these depths. The composition of the outer core is primarily iron and nickel, which contribute to its fluidity. This molten state is critical as it plays a significant role in generating Earth's magnetic field through the process of convection and the movement of these molten metals. In addition to its composition and state, the outer core lies beneath the mantle and above the solid inner core. Knowing the characteristics of the outer core is essential for understanding the dynamics of the Earth's interior, including processes such as plate tectonics and magnetic field generation. The other options do not accurately describe the outer core's properties, leading to the conclusion that it is indeed a layer of molten iron and nickel.