Because of gravity, and an effect gravity creates that we call weight. Substances that weigh less will rest (in liquids or gas, float) above substances that weigh more. Gravitationally significant objects, such as planets, will tend to sift their materials; heavier materials will settle lower through the lighter ones. Also, the lower materials are compressed by the weight of the material above them (which amplifies the density of the lower material); this is why despite it all being made of seawater, pressure at lower ocean depths is much greater than the pressure of ocean water near the surface and also why air is thinner the higher in altitude you go -- in oceans, the bottommost oceanwater is compressed by the weight of all the ocean water above it and in the atmosphere, the air at the surface is compressed to the air pressure we are familiar with by the weight of the atmosphere above.
Core
Toposphere, Stratosphere, Mesosphere and Thermosphere
There is no "purpose"; the density of the materials in the outer core are less pressured and spin slower than the inner core. NOTE: the inner core spins faster than the outer, creating Earth's magnetic field.
Both temperature and pressure increase.
the solid layer of the earth id the inner core. The inner core is made up of solid iron and nickel.
Increase in the core temperature and decrease in the core radius.
The core has the highest density among the crust, mantle, and core. This is because the core is composed mainly of iron and nickel, which are heavy elements that increase its overall density compared to the other layers of the Earth.
Temperature, pressure, and density increase as you move from the Earth's crust to the inner core.
The density of Earth material increases as you approach the core. This is due to the composition and pressure conditions; the inner core, primarily composed of iron and nickel, is much denser than the outer layers. As depth increases, the immense pressure compresses the materials, leading to higher densities. Consequently, the overall trend is an increase in density from the surface to the core.
The layers of the Earth in order of increasing density are the crust, the mantle, the outer core, and the inner core. The inner core is the most dense layer due to the high pressure at its center.
At the mantle-core boundary, there is a change in density and composition of the material. The increase in density and the solid state of the core allow P waves to travel through, with some refraction due to the change in velocity.
As you go deeper into the Earth, both temperature and density increase. The increase in temperature is due to the Earth's molten core and radioactive decay in the mantle. Density increases because of the weight of the overlying rock pushing down on the material below.
As you go deeper into the Earth, the temperature and pressure increase. Additionally, you may encounter different layers of the Earth's interior, such as the crust, mantle, outer core, and inner core. The density of materials also tends to increase as you move towards the Earth's center.
The density of Earth's layers increases as you move towards the Earth's core. This is because the core is made up of denser materials such as iron and nickel, which causes an increase in density compared to the less dense outer layers.
The pressure is highest in the troposphere, the layer closest to the Earth's surface. As altitude increases, the pressure decreases in the troposphere due to the decreasing density of gases in the atmosphere.
The inner core has the most or highest amount of density (iron/nickel).
The transition from the outer core to the lower mantle, known as the core-mantle boundary, is a region where there is a dramatic decrease in material density inside the Earth. This boundary is characterized by a significant change in the physical properties of the materials, such as a decrease in density and an increase in seismic wave velocity.