GEOLOGY

Detailed explanation-1: -The inner core is solid, the outer core is liquid, and the mantle is solid/plastic. This is due to the relative melting points of the different layers (nickel–iron core, silicate crust and mantle) and the increase in temperature and pressure as depth increases.

Detailed explanation-2: -The entire iron and nickel core is extremely hot, so it is not surprising to learn that the outer core is in a molten state. However, the inner core’s iron and nickel are solid.

Detailed explanation-3: -The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth’s magnetic field.

Detailed explanation-4: -The outer core is not under enough pressure to be solid, so it is liquid even though it has a composition similar to that of the inner core. Sulfur and oxygen could also be present in the outer core.