Question

which statement best explains why earths outer core is in liquid form?
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.

Explanation:

The Earth's outer - core is composed mainly of an iron - nickel alloy. High temperatures in the outer core cause this alloy to melt, resulting in a liquid state. The other options are incorrect as the tarry consistency is not the main reason for the liquid state, the outer core is denser than the mantle, and extreme pressure actually tends to keep materials in a solid state (but high temperature overcomes this in the outer core).

Answer:

The iron - nickel alloy melts due to hot temperatures.