The metallic layer at Earth's center is called the inner core. It's a solid ball of mostly iron with a small amount of nickel.

Here's a breakdown of the Earth's layers:

* Crust: The thin, rocky outer layer we live on.

* Mantle: A thick layer of mostly solid rock, but it can flow very slowly over long periods.

* Outer core: A liquid layer of iron and nickel. This is where Earth's magnetic field is generated.

* Inner core: A solid ball of iron and nickel, despite the intense heat and pressure.

The inner core is incredibly hot, estimated to be around 5,200 °C (9,392 °F), but the immense pressure keeps it from melting. This pressure is so great that the iron atoms are squeezed together tightly, making the inner core solid.