Why is the outer core the only layer in Earth that is molten?
A)The pressure decreases within Earth,thus allowing iron to melt.
B)The pressure increases within Earth,thus allowing iron to melt.
C)The temperature is high enough but pressure low enough to melt iron.
D)The temperature is high enough but pressure low enough to melt olivine.

Question

Quizplus · Accepted Answer

The outer core is the only layer in Earth that is molten because the temperature is high enough to melt iron (which is mostly what the outer core is made of), but the pressure is low enough to allow it to remain in a liquid state. In the inner core, the pressure is too high for the iron to remain in a liquid state, and in the mantle, the temperature is not high enough to melt the rocks (mostly olivine) that make up the layer.

Why Is the Outer Core the Only Layer in Earth