Mantle is like silly putty consistency. It is the largest layer of Earth sitting under the Crust. It is made roughly from silicon, oxygen, iron, and magnesium. The layer is composed almost entirely of magma - molten rock inside the earth. The mantle is about 2,900km thick. The mantle gets warmer with depth; the top of the mantle is about 870° C, headed for the bottom of the mantle, the temperature is about 2,200-3,700° C.
Outer Core is the third layer. This level is basically liquid. Most of this layer is made from liquid nickel and iron. Outer Core is about 2,200km thick. The temperature of the Outer Core is 4000-5000°C.
Inner Core is the fourth layer of the Earth. The thickness of the Inner Core is 1,250km and mainly consists of iron, nickel and some lighter elements (probably sulphur, carbon, oxygen, silicon and potassium. The temperature in the inner core is about 5000-6000°C, it is the hottest layer of the Earth. Because of the high pressure, the core is solid. If a person were to travel that deep, they would burn up with in the Mantle before they ever came near the core. Even with a ship that could withstand the high temperature, it would be crushed by the great pressure.