Earth's Layers
What are the three main layers of the Earth?
Crust, Mantle, Core
What is a mineral?
A naturally occurring, inorganic solid with a definite chemical composition.
What process breaks rocks into smaller pieces?
Weathering
What supercontinent did Alfred Wegener propose once existed?
Pangaea
What is a meteor?
A streak of light from space debris burning in Earth’s atmosphere.
What causes day and night?
Earth’s rotation.
Which layer of Earth is the thickest?
Mantle
Which rock type forms from cooled magma or lava?
Igneous rock
What process moves sediment from one place to another?
Erosion
What type of plate boundary occurs when plates move apart?
Divergent boundary
What is a meteorite?
A meteor that reaches Earth’s surface.
What causes the seasons?
Earth’s tilt and revolution around the Sun.
Which part of the core is liquid?
Outer core
Which rock type forms from heat and pressure?
Metamorphic rock
What process occurs when sediment is dropped in a new location?
Deposition
What type of boundary occurs when plates collide?
Convergent boundary
Where are most asteroids located?
The asteroid belt between Mars and Jupiter.
How tilted is Earth’s axis?
About 23.5 degrees.
What causes tectonic plates to move?
Convection currents in the mantle
Which rock type forms from compacted and cemented sediment?
Sedimentary rock
Name two agents of erosion.
Wind, water, ice, or gravity
What type of boundary occurs when plates slide past each other?
Transform boundary
What are comets mostly made of?
Ice, dust, and rock.
What is one full orbit of Earth around the Sun called?
Revolution.
Which layer has the highest temperature, pressure, and density?
Inner core / Core
Why are fossils usually found in sedimentary rock?
Because sediment forms in layers that preserve remains without destroying them.
What type of weathering occurs when acid rain dissolves rock?
Chemical weathering
What happens when an oceanic plate collides with a continental plate?
Subduction occurs (oceanic plate sinks).
Why do comet tails point away from the Sun?
Solar wind pushes gas and dust away.
What would happen if Earth were not tilted?
We would not have seasons.