Which statement best explains why Earth’s outer core is in liquid form?

Question

The iron-nickel alloy melts due to hot temperatures.
The outer core has a tarry consistency.
This region is less dense when compared to the mantle.
This region is under extreme pressure from the weight of other layers.

Answer 1

The statement that best explains why Earth’s outer core is in liquid form is:

The iron-nickel alloy melts due to hot temperatures.

While extreme pressure does affect the state of matter, the high temperatures in the outer core are primarily responsible for keeping the iron-nickel alloy in a liquid state. The combination of high temperature and the properties of the materials involved leads to the outer core being liquid.