The tests used to determine whether brain stem death has occurred are outlined below: 1  A torch is shone into both eyes to see if they react to the light. 2  The cornea (transparent outer layer of the eye), which is usually very sensitive, is stroked with a tissue or piece of cotton wool to see if the eye reacts.
The inner core extends another 900 miles inward towards the center of the Earth. It is believed that this inner core is a solid ball of mostly iron, and nickel. The mantle is made of much denser, thicker material, because of this the plates float on it like oil floats on water.
The Lower Mantle- part of the second layer of the earth which is mostly melted rock. The whole mantle going down is 1800 miles down. The Outer Core- is made up of liquid metals mostly iron nickel and minor sulfur. The outer core goes 1375 miles down. The Inner Core- the most inner layer of the earth which is solid and made of iron and nickel. The inner core is 1750 miles to the center. How the layers of the Earth were created.