100 points!! word bank! ⬇️Article⬇️
Have you ever cut an apple in half and looked at the layers inside? When you cut something in half, the resulting view is called a cross section. When you look at the cross section of an apple, you see several layers: the skin, the pulp, the core, and the seeds. Much like the apple, Earth is made up of layers, too. If you could look at a cross section of our planet, you would see the crust. the mantle, the outer core, and the inner core. If Earth were an apple, the crust would be the apple’s skin. The mantle would be the apple’s pulp, making up most of the inside. Earth also has a central core, similar to an apple’s core, though Earth’s core does not contain any seeds! Of course, scientists cannot cut the whole planet in half to see a cross section the way you can with an apple. How do you think scientists know about Earth’s internal layers?

Scientists divide Earth’s interior into distinct layers.

Scientists can distinguish different layers in Earth depending on the properties used to identify each layer. For example, scientists identify the crust, mantle, and core based on each layer’s basic chemical composition. In other words, the crust, mantle, and core are each made up of different chemical elements. The crust and mantle are composed primarily of the elements oxygen and silicon. These are known as silicates. Silicates of the mantle contain heavier elements. This makes them denser than those found in the crust. The core is composed of the densest materials, primarily iron and nickel. Earth’s layers can also be identified by using each layer’s physical state of matter. The crust and the uppermost part of the mantle, together, make up a layer called the lithosphere. The lithosphere is the cool, rigid, outermost layer of Earth. The lithosphere is in the solid
In a typical silicate molecule, a silicon atom is bonded to four oxygen atoms. The atoms form a crystal structure.

Scientists use models to represent the different layers of Earth’s interior.

When constructing a model of the layers of Earth, scientists need to consider the chemical composition, state of matter, and thickness of each layer. Just like the skin of an apple, Earth’s crust is very thin compared to the other layers. It is about 25–70 km thick beneath the continents. Under the oceans, the crust is only about 5–7 km thick; however, it is much denser. The mantle is much thicker than the crust is, taking up most of Earth’s volume. The mantle begins directly beneath Earth’s crust. It reaches all the way to the outer core, about 2,900 km below the planet’s surface. In other words, Earth is about 1% crust, 83% mantle, and 16% core.

The crust and uppermost mantle are solid. The rest of the mantle is solid with plasticity. The core is made of very dense iron and nickel. The outer core is liquid, because it is hot enough to melt the iron and nickel. The inner core is solid. Even though it is as hot as the outer core, there is so much pressure at the very center of Earth that the iron and nickel stay in a solid state.

Looking to the Future: Exploring Earth’s Interior

Despite what you may have read in stories or seen in movies, scientists have never journeyed to the center of Earth. In fact, scientists have never made it through Earth’s crust! However, this has not stopped them from trying. The crust at the bottom of the oceans is much thinner than the crust of the continents. Therefore, drilling through the oceanic crust is the best chance that scientists have to make it to the mantle.