Earth's Atmosphere and interior - Chapter 4

The atmosphere is divided into layers based on differences in _______.

temperature

The troposphere, where weather occurs, extends from the surface to about _______ km in altitude.

17

As altitude increases in the troposphere, temperature _______.

decreases

The ozone layer, which absorbs harmful UV radiation, is located in the _______ layer of the atmosphere.

stratosphere

Unlike the troposphere, temperatures in the stratosphere _______ with altitude.

increase

The coldest temperatures in the atmosphere are found in the _______.

mesosphere

The layer with the highest temperatures due to direct solar radiation absorption is the _______.

thermosphere

In the heterosphere (above 80 km), gases are _______ rather than mixed evenly.

layered

The most abundant gas in Earth's atmosphere is _______.

nitrogen

The second most abundant gas in the atmosphere, essential for respiration, is _______.

oxygen

A key greenhouse gas that traps heat and contributes to warming is _______.

carbon dioxide

Unlike permanent gases, such as nitrogen and oxygen, variable gases like _______ change in concentration depending on location and weather.

water vapor

The lithosphere, which includes the crust and upper mantle, is _______ and solid.

rigid

The asthenosphere, which allows plates to move, is partially _______

molten

Convection currents in the _______ drive the slow movement of Earth's tectonic plates.

mantle

The _______ is the thickest layer of Earth's interior and is composed of solid and molten rock.

mantle

The inner core is composed primarily of _______.

Iron

Unlike the solid inner core, the outer core is in a _______ state.

liquid

The _______ crust is less dense but thicker than the _______ crust, which is denser but thinner.

continental, oceanic

The oceanic crust is primarily composed of _______ rock.

basalt

The continental crust is mostly composed of _______ rock.

granite

The boundary between the crust and mantle, where seismic waves change speed, is called the _______.

Moho (Mohorovičić Discontinuity)

The lapse rate refers to how _______ changes with increasing altitude.

Temperature

The average lapse rate in the troposphere is _______°C per 1000 meters.

6.4

How does the composition of the atmosphere influence weather and climate?

The atmosphere's composition controls temperature regulation, weather patterns, and greenhouse effects. For example, oxygen enables respiration, carbon dioxide traps heat, and water vapor influences humidity and precipitation.

The inner core is hotter than the outer core, yet it remains solid. Why?

The immense pressure in the inner core prevents the iron from melting, keeping it solid despite the high temperatures.

The troposphere is the most important layer for humans because it contains _______.

weather

The boundaries between atmospheric layers, where temperature changes suddenly, are called _______.

pauses (e.g., tropopause, stratopause)

Even though temperatures in the thermosphere can reach over 1200°C, it feels cold because the air is extremely _______.

thin

As altitude increases, atmospheric pressure _______.

decreases

The gas responsible for absorbing harmful ultraviolet (UV) radiation in the stratosphere is _______.

ozone (O₃)

When snow and ice melt, Earth's albedo _______ and causes more warming.

decreases

The process where certain gases trap heat in Earth's atmosphere is called the _______ effect.

greenhouse

The movement of Earth's tectonic plates is driven by _______ currents in the mantle.

convection

The _______ core generates Earth's magnetic field due to the movement of molten iron.

Outer

The oldest crust on Earth is found in the _______ crust.

continental

Why is the atmosphere divided into distinct layers instead of being uniform throughout?

Atmospheric layers form due to changes in temperature and gas composition. Each layer has different properties because of solar radiation absorption, pressure, and density differences.

The Atmosphere is divided into distinct layers based on _______, _________, and __________.

Composition, temperature, and function

What is the correct order of the atmospheric layers from the Earth's surface upward?

Troposphere, Stratosphere, Mesosphere, Thermosphere

Which layer of the atmosphere contains the ozone layer, which absorbs harmful ultraviolet radiation?

Stratosphere

The layer of the atmosphere where weather occurs and where most clouds are found is the _________

Troposphere

What is the most abundant gas in the Earth's atmosphere?

Nitrogen (N₂)

The homosphere extends from _________ km to _________ km and has gases that are well mixed.

0 km to 80 km

The heterosphere differs from the homosphere because:

It contains layered gases based on atomic weight

The four main layers of Earth's interior are the _________, _________, _________, and _________.

Lithosphere, Mantle, Outer Core, Inner Core

What characteristic of the outer core makes it unique?

It is a liquid layer responsible for Earth’s magnetic field

The boundary between Earth's crust and mantle, where seismic waves change speed, is cal

Moho Discontinuity

The mantle is mostly composed of the rock _________, and its movement drives _________ activity.

Peridotite, plate tectonic

Which of the following statements about continental and oceanic crust is true?

Oceanic crust is denser than continental crust

The continental crust is primarily composed of _________ and _________,

Silica & Aluminum (Si & Al),

while the oceanic crust is composed of _________ and _________.

Silica & Magnesium (Si & Mg)

Compared to continental crust, oceanic crust is:

Denser and thinner

Scientists discover a new exoplanet with a thicker, denser atmosphere than Earth's. What would be the most likely consequence of this?

More extreme weather patterns

A region is experiencing significant volcanic activity. What layer of Earth is most directly involved in fueling this activity?

Asthenosphere

What is the first key relationship regarding the atmosphere and gas composition?

As altitude increases, air density decreases because there are fewer gas molecules per unit volume at higher elevations.

What is the second key relationship regarding atmospheric pressure?

Air pressure is highest at the surface because the weight of the atmosphere is pressing down. As altitude increases, less air mass is above, so pressure decreases.

What is the third key relationship regarding energy transfer in the atmosphere?

Heat Transfer Mechanisms (Conduction, Convection, Radiation)

• Conduction: Heat transfer through direct contact (e.g., ground heating air).

• Convection: Heat movement through fluids (e.g., warm air rising).

• Radiation: Heat transfer through electromagnetic waves (e.g., solar radiation warming Earth).

What is the relationship between pressure and atmospheric gases?

• Pressure is the force exerted by the weight of the air on a surface.

• As altitude increases, atmospheric pressure decreases because there are fewer air molecules pressing down.

• This is why mountaineers need oxygen tanks at high altitudes.

How does temperature influence atmospheric gases?

• Temperature affects the movement of gases in the atmosphere.

• Warmer air expands and rises, while cooler air contracts and sinks.

• This drives weather patterns and wind movement.

What are the three key relationships between the atmosphere, gas composition, and pressure?

• Density Decreases with Altitude – The higher you go, the lower the density of air molecules.

• Atmospheric Pressure Decreases with Altitude – Less air above means lower weight pressing down.

• Temperature Changes with Altitude – Different layers of the atmosphere warm or cool at different rates due to radiation absorption.

How does air density change with altitude in the atmosphere?

Air density decreases with altitude because there are fewer gas molecules the higher you go.

Why does atmospheric pressure decrease with altitude?

There is less air above exerting force, meaning lower pressure at higher altitudes.

How does temperature vary through the troposphere

Temperature decreases with altitude.

How does temperature vary through stratosphere?

Temperature increases due to ozone absorption of UV radiation.

How does temperature vary through the Mesosphere:

Temperature decreases again.

How does temperature vary through

Temperature increases due to direct absorption of solar energy.

What is the lithosphere?

The rigid outer shell of Earth, including the crust and upper mantle. It is broken into tectonic plates that move over the asthenosphere.

How does the lithosphere interact with the asthenosphere?

The lithosphere "floats" on the asthenosphere, which is more ductile and allows for plate movement. Convection currents in the asthenosphere drive tectonic activity like earthquakes and volcanoes.

What role does the asthenosphere play in plate tectonics?

The asthenosphere is semi-solid and allows for plate movement due to slow-flowing convection currents beneath the lithosphere.