GEOLOGY

Detailed explanation-1: -The densest layer (inner core) is at the center and the least dense layer (crust) is the outermost layer. The atmosphere, composed of gases, can technically be considered a layer as well and is obviously lighter than the crust.

Detailed explanation-2: -Due to increase in pressure and presence of heavier materials like Nickel and Iron towards the centre, the density of earth’s layers also gets on increasing towards the centre. The average density of the layers gets on increasing from crust to core and it is nearly 14.5g/cm3 at the very centre.

Detailed explanation-3: -The inner core is the deepest layer on Earth. It is also made up of iron and nickel but the pressure is so high that it is no longer liquid. The temperatures in the inner core are as hot as the surface of the sun, about 5505 °C. Earth’s inner core is 1, 230 to 1, 530 km thick.