Earth’s inner core is ______.
*
3 points
A dense ball of solid metal
A layer of molten liquid metal
A layer of hot rock
A layer of rock that forms Earth’s outer skin
A dense ball of solid metal.
Earth's inner core is a dense ball of solid metal.
To determine the correct answer to this question, we can rely on scientific research and knowledge about the Earth's structure. Let's go through each option and explain how we can identify the correct answer.
Option 1: A dense ball of solid metal
To determine if Earth's inner core is a dense ball of solid metal, scientists have used seismic waves, specifically shear waves, to study the Earth's interior. Shear waves cannot propagate through liquids or gases, but they can travel through solids. By analyzing the behavior of these waves, scientists have confirmed that the Earth's inner core is solid.
Option 2: A layer of molten liquid metal
Although this option may seem plausible, it is actually referring to the outer core of the Earth, not the inner core. The outer core, located beneath the Earth's mantle, is composed mostly of molten liquid metal. This layer is responsible for generating the Earth's magnetic field.
Option 3: A layer of hot rock
Similarly to the previous option, this description fits the Earth's mantle, not the inner core. The mantle is a layer of hot, semi-solid rock situated between the Earth's crust and the core. It plays a crucial role in the movement of tectonic plates.
Option 4: A layer of rock that forms Earth’s outer skin
This option describes the Earth's crust, which is the outermost layer of the Earth. The crust consists of solid rock and is the thinnest of the Earth's layers.
Therefore, the correct answer is: A dense ball of solid metal. The inner core of the Earth is predominantly composed of solid metal, primarily iron and nickel, due to intense pressure that keeps it in a solid state despite high temperatures.