Answer:
The rock is so hot, however, that it flows under pressure, like road tar. This creates very slow-moving currents as hot rock rises from the depths and cooler rock descends. The mantle is about 1,800 miles (2,900 kilometers) thick and appears to be divided into two layers: the upper mantle and the lower mantle.
Even though the inner-core temperature is now thought to be hotter than the Sun's surface, the tremendous pressure this deep inside the Earth overrides the effects of temperature and prevents the iron from being liquefied. Instead, the iron at the core is a solid and has a spherical shape.
Explanation:
