* High Temperatures: The Earth's interior is extremely hot due to the heat generated from radioactive decay and the leftover heat from the Earth's formation. Temperatures in the outer core are estimated to be around 4,500-5,500°C (8,132-9,932°F).
* Pressure: Despite the high temperatures, the outer core remains liquid because the immense pressure from the overlying mantle and crust keeps the material from solidifying. Pressure increases the melting point of materials, so even though the temperature is high enough to melt iron and nickel at the surface, it's not high enough to melt them at the core's depth.
* Composition: The outer core is primarily composed of iron and nickel, along with smaller amounts of other elements such as sulfur and silicon. These elements have relatively low melting points compared to other elements found in the Earth's mantle.
In summary, the high temperature, immense pressure, and the specific composition of the outer core create conditions where iron and nickel remain in a liquid state.
It's important to note that the outer core isn't completely liquid, but more like a "molten slurry" with a viscosity similar to water. The liquid iron in the outer core is constantly moving due to convection currents, generating the Earth's magnetic field.
