Composition of the layers of the earth

Question 1

What is the average density of the Earth as determined by Cavendish?

Answer 1

5.5g/cm^3

Question 2

Which of the following meteorites are believed to closely represent the Earth’s original composition?

Answer 2

Carbonaceous chondrites

Question 3

What is the main component of the upper mantle rock called peridotite?

Answer 3

Olivine and pyroxene

Question 4

What technique is used to model Earth’s interior using seismic wave data?

Answer 4

Seismic tomography

Question 5

Why does the oceanic crust have higher iron and magnesium than the continental crust?

Answer 5

It is derived from partially melted mantle

Question 6

What is the density range of the Earth’s inner core?

Answer 6

12.6–13.0 g/cm³

Question 7

What is the magma ocean hypothesis?

Answer 7

A theory that Earth’s early interior was fully molten due to heat from core formation

Question 8

What process explains the formation of distinct layers inside the Earth?

Answer 8

Differentiation (fractionation)

Question 9

Which two minerals are polymorphs formed from Mg₂SiO₄ under different pressures in the mantle?

Answer 9

Olivine and Wadsleyite

Question 10

What percent of Earth’s mass is made up by the mantle?

Answer 10

~67%