Question

1. which of the following most likely causes earth’s inner core to be a solid?

a) the pressure in the core is very high
b) the metals in the core are very heavy
c) the temperature of the core is very low
d) the chemicals in the core are very reactive

1. the composition of the outer core is:

a) primarily granite and basalt
b) a cool, solid layer
c) made primarily of liquid iron
d) a solid made of iron and nickel
7 record the 1st letter of each word in the correct order with a comma in between.
5 record the correct letter
6
4

Explanation:

Question 5

To determine what causes Earth’s inner core to be solid, we analyze the options:

• Option a: High pressure in the core increases the melting point of metals (like iron/nickel), forcing them to solidify despite high temperature. This matches scientific understanding of the inner core’s state.
• Option b: Heavy metals alone don’t explain solidity (pressure is key).
• Option c: The core’s temperature is extremely high (not low), so this is incorrect.
• Option d: Core chemicals (iron/nickel) are not “very reactive” in a way that causes solidity; pressure is the driver.

Thus, high pressure (option a) is the correct cause.

The outer core’s composition:

• Option a: Granite (crust) and basalt (mantle/crust) are not core materials.
• Option b: The outer core is liquid (not solid), so this is incorrect.
• Option c: The outer core is primarily liquid iron (and nickel), which matches geological knowledge.
• Option d: Solid iron/nickel describes the inner core, not the outer core.

Thus, the outer core is made primarily of liquid iron (option c).

Answer:

a. The pressure in the core is very high

Question 6