Question

scientists have discovered that the inner core of earth is a solid while the outer core is a liquid. what is the cause of this observation?
the inner core has a higher temperature and lower pressure than the outer core
the inner core has a lower temperature and higher pressure than the outer core
the outer core has a lower temperature and lower pressure than the inner core
the outer core has a higher temperature and more pressure than the inner core

Explanation:

The state of matter (solid or liquid) of a substance depends on both temperature and pressure. The inner core is solid because it has a higher pressure than the outer core. Higher pressure can keep materials in a solid state even at high temperatures.

Answer:

The outer core has a lower pressure than the inner core.