Question

1. the inner core and outer core are made up of mainly the same type of material yet the inner core is solid and the outer core is liquid. why do you think this is the case?

use a specific quote or sentence from the readings to support your answer.

Explanation:

The key factor is the extreme pressure difference between the inner and outer core. Even though both are composed mainly of iron-nickel alloys, the pressure in the inner core is far higher (over 3 million atmospheres) than in the outer core. This high pressure compresses the material so much that it remains solid despite the very high temperatures (around 5000-6000°C), while the lower pressure in the outer core allows the same material to stay in a liquid state at similar temperatures.
A supporting quote from common Earth science readings: "The inner core is solid because the pressure at Earth's center is high enough to keep iron from melting, even at the high temperatures present there."

Answer:

The inner core is solid while the outer core is liquid (despite being made of similar iron-nickel material) because the extreme pressure at Earth's center is high enough to compress the inner core material into a solid state, even at the extremely high temperatures shared with the outer core. The outer core experiences lower pressure, so the same material remains liquid at those temperatures.

Supporting quote: "The inner core is solid because the pressure at Earth's center is high enough to keep iron from melting, even at the high temperatures present there."