ESB -U2Q1: Earth's Layers Pulse Check - 2025

What is the independent variable on the graph below?

• Velocity (km/s)
• Seismic waves
• Depth (km)

Early Earth (proto-Earth) was a _____ planet.

• differentiated
• heterogeneous
• homogeneous
• layered

Heavy (dense) elements were separated from lighter (less dense) elements within early Earth during a phenomenon known as _____.

• the Cambrian Explosion
• Primary Endosymbiosis
• the Great Oxidation Event
• the Iron Catastrophe
• Plate Tectonics

Most of the water on Earth's surface originated from _____.

• Earth's interior
• comets
• an icy ring system
• dinosaur tears

True/False: Earth's first crust was formed when a magma ocean solidified into rock.

• True
• False

Based on chemical composition, Earth has _____ layers.

• 2
• 3
• 4
• 5

Identify the least dense layer of Earth:

• asthenosphere
• inner core
• lithosphere
• lower mantle
• outer core

Identify the hottest layer of Earth:

• asthenosphere
• inner core
• lithosphere
• lower mantle
• outer core

Identify the layer that consists of molten rock:

• asthenosphere
• inner core
• lithosphere
• lower mantle
• outer core

Which of the following statements is true?

• Continental crust is much thicker and less dense than oceanic crust
• Continental crust is much thicker and more dense than oceanic crust
• Oceanic crust is much thicker and more dense than continental crust
• Oceanic crust is much thicker and less dense than oceanic crust