SOLAR SYSTEM

Detailed explanation-1: -Earth’s core was formed very early in our planet’s 4.5 billion-year history, within the first 200 million years. Gravity pulled the heavier iron to the centre of the young planet, leaving the rocky, silicate minerals to make up the mantle and crust. Earth’s formation captured a lot of heat within the planet.

Detailed explanation-2: -Many geologists believe that as the Earth cooled the heavier, denser materials sank to the center and the lighter materials rose to the top. Because of this, the crust is made of the lightest materials (rock-basalts and granites) and the core consists of heavy metals (nickel and iron).

Detailed explanation-3: -There are two reasons. First, the Earth formed from the same kind of material as the asteroids but early in Earth’s history the iron-nickel metal that it contained sank to form the Earth’s core. Second, any metal that did not sink has oxidized (rusted) over Earth’s long history.

Detailed explanation-4: -The mantle is the mostly solid bulk of Earth’s interior. The mantle lies between Earth’s dense, super-heated core and its thin outer layer, the crust. The mantle is about 2, 900 kilometers (1, 802 miles) thick, and makes up a whopping 84 percent of Earth’s total volume.

Detailed explanation-5: -However, unlike the outer core, the inner core is not liquid or even molten. The inner core’s intense pressure-the entire rest of the planet and its atmosphere-prevents the iron from melting. The pressure and density are simply too great for the iron atoms to move into a liquid state.