Here's why:

* Earth's Layers: The Earth is made up of several layers: the crust, upper mantle, lower mantle, outer core, and inner core.

* Outer Core Composition: The outer core is primarily composed of liquid iron and nickel, with small amounts of other elements like sulfur and silicon.

* High Temperature and Pressure: The immense pressure and extreme heat within the Earth's core are what keep the iron in a molten state.

Let me know if you have any other questions!