LT 2.2 Practice Quiz

Which layer of the Earth is primarily composed of solid rock and forms the outermost shell?

• Mantle

• Crust

• Outer core

• Inner core

Answer explanation

The crust is the Earth's outermost layer, primarily composed of solid rock. It is distinct from the mantle, which lies beneath it, and the core layers, which are primarily liquid and solid metals.

What is the main state of matter of the Earth's outer core?

• Solid

• Liquid

• Gas

• Plasma

Answer explanation

The Earth's outer core is primarily in a liquid state, composed mainly of molten iron and nickel. This liquid layer surrounds the solid inner core and is responsible for generating the Earth's magnetic field.

Tags

NGSS.MS-PS1-1

Which element is most abundant in the Earth's inner core?

• Oxygen

• Iron

• Silicon

• Magnesium

Answer explanation

Iron is the most abundant element in the Earth's inner core, making up about 80% of its composition. This high concentration is due to iron's density and its ability to remain solid under the extreme pressure and temperature conditions.

Tags

NGSS.MS-PS1-1

Which layer of the Earth is the thickest?

• Crust

• Mantle

• Outer core

• Inner core

Answer explanation

The mantle is the thickest layer of the Earth, extending about 2,900 kilometers (1,800 miles) deep, while the crust is much thinner and the outer and inner cores are denser but not as thick as the mantle.

What is the approximate thickness of the Earth's crust?

• 5–70 km

• 2,900 km

• 2,200 km

• 1,200 km

Answer explanation

The Earth's crust varies in thickness, typically ranging from 5 km under oceans to about 70 km under continental regions. Therefore, the correct answer is 5–70 km.

Tags

NGSS.MS-ESS2-1

Which process in the mantle is responsible for the movement of tectonic plates?

• Radiation

• Convection

• Conduction

• Sublimation

Answer explanation

Convection in the mantle involves the movement of hot, less dense material rising and cooler, denser material sinking. This process drives the movement of tectonic plates on the Earth's surface.

Tags

NGSS.MS-ESS2-3

Which layer is directly beneath the Earth's crust?

• Outer core

• Mantle

• Inner core

• Lithosphere

Answer explanation

The layer directly beneath the Earth's crust is the mantle. It is a thick layer of semi-solid rock that extends to the outer core, while the outer core and inner core are located deeper within the Earth.

What is the primary composition of the Earth's continental crust?

• Basalt

• Granite

• Iron

• Nickel

Answer explanation

The Earth's continental crust is primarily composed of granite, which is a light-colored igneous rock rich in silica and aluminum. In contrast, basalt is more common in oceanic crust, while iron and nickel are primarily found in the Earth's core.

Which layer of the Earth is responsible for generating the planet’s magnetic field?

• Crust

• Mantle

• Outer core

• Inner core

Answer explanation

The Earth's magnetic field is generated by the movement of molten iron and nickel in the outer core. This fluid motion creates electric currents, which in turn produce the magnetic field, making the outer core the correct answer.

What is the state of matter of the Earth's inner core?

• Gas

• Liquid

• Solid

• Plasma

Answer explanation

The Earth's inner core is primarily composed of iron and nickel, and it exists in a solid state due to the immense pressure at that depth, despite the high temperatures. Therefore, the correct answer is 'Solid'.