Composition of Air and Layers of Atmosphere

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Questions and Answers

Which layer of the atmosphere is known for containing most of Earth's ozone and absorbing ultraviolet light?

Mesosphere

Thermosphere

Stratosphere (correct)

Troposphere

The thermosphere is the coldest layer of the atmosphere.

False

What process is responsible for producing oxygen on Earth?

Photosynthesis

The atmosphere is composed of approximately ____% nitrogen.

78 Signup and view all the answers

Match the following layers of atmosphere with their characteristics:

Troposphere = Weather occurs here Stratosphere = Contains ozone layer Mesosphere = Burns up meteors Exosphere = Fades into space Signup and view all the answers

Which of the following gases changes concentration seasonally in the atmosphere?

Carbon Dioxide Signup and view all the answers

Albedo refers to the ability of a substance to absorb light.

False Signup and view all the answers

What is the main reason the mesosphere gets colder as altitude increases?

There is less material to absorb sunlight. Signup and view all the answers

What is the relationship between temperature and particle speed?

Faster particles are hotter. Signup and view all the answers

The dew point is the temperature at which the air is completely saturated.

True Signup and view all the answers

What is the formula for density?

D = M/V Signup and view all the answers

Air pressure at sea level is approximately _______ lbs per square inch.

14.7 Signup and view all the answers

Match the following weather phenomena with their descriptions:

Hail = Frozen raindrops blown upward that grow larger Sleet = Liquid that freezes on the way down Snow = Water vapor turning directly into solid Rain = Liquid water droplets precipitating from clouds Signup and view all the answers

Which of the following statements is true regarding humidity?

Humidity is a measure of the amount of water vapor in the air. Signup and view all the answers

Wind always blows from areas of low pressure to high pressure.

False Signup and view all the answers

What is the main driver behind the movement of air, or wind?

Changes in pressure Signup and view all the answers

The process of water vapor turning into liquid water droplets in the atmosphere is called _______.

condensation Signup and view all the answers

Which part of the Kinetic Molecular Theory (KMT) states that faster particles correspond to higher temperatures?

Faster particles indicate higher temperatures. Signup and view all the answers

Study Notes

Composition of Air

Air is a mixture of gases, primarily nitrogen (78%) and oxygen (21%).
Argon and trace amounts of other gases make up the remaining percentage.
Early Earth lacked oxygen, but photosynthesis produced it.

Layers of the Atmosphere

Troposphere:
- Contains most of the atmosphere's mass.
- Weather occurs here.
- Temperature decreases with altitude.
- Extends 9-16 km (5-8 mi) above Earth's surface.
Stratosphere:
- Chemical reactions absorb ultraviolet light.
- Contains most of the Earth's ozone.
- Temperature increases with altitude due to ozone absorption.
- Extends 50 km (30 mi) above Earth's surface.
Mesosphere:
- Very thin, absorbs little sunlight.
- Temperature decreases with altitude.
- Meteors burn up here.
- Extends 85 km (52 mi) above Earth's surface.
Thermosphere:
- Hottest layer.
- Extends 600 km (375 mi) above Earth's surface.
- Satellites and the ISS orbit here.
- Aurora Borealis (Northern Lights) occur.
Exosphere:
- Outermost layer, gradually fades into space.
- No clear upper boundary.

Energy in the Atmosphere

Temperature vs. Heat:
- Temperature measures the average speed of particles.
- Heat is the transfer of thermal energy from hotter to colder.
Heat Transfer:
- Sunlight transfers thermal energy through space.
- Darker surfaces absorb sunlight, lighter surfaces reflect it.
- Albedo is the ability to reflect light; fresh snow has the highest.
- Conduction transfers heat when surfaces touch; atmosphere touches Earth.
- Convection involves rising (hot, less dense) and falling (cold, more dense) air. Creates convection cells.
Greenhouse Effect:
- The atmosphere traps heat, maintaining temperatures suitable for life.

Temperature & Humidity

Temperature:
- Measured in Celsius (°C).
- Water freezes at 0°C and boils at 100°C.
Humidity:
- Amount of water vapor in the air.
- Warmer air holds more water vapor than colder air.
- When air is "full" (saturated), it cannot hold more water vapor.
- Relative humidity measures how close the air is to saturation.
- Dew point is the temperature at which water vapor condenses.
- Frost forms if dew point is below freezing.

Air Pressure

Air pressure is the force exerted by air on a surface.
Higher altitudes have lower pressure.

Density

Density is mass per unit volume.
Warm air is less dense; Cold air is more dense.
Pressure affects air density.

Wind and Precipitation

Wind:
- Movement of air caused by pressure differences
- Blows from high to low pressure
- Speed affected by pressure difference, obstacles (hills, buildings).
Precipitation:
- Water falling from the atmosphere (rain, hail, sleet, snow).
- Forms when water vapor condenses into liquid or solid water.
  - Hail: raindrops frozen repeatedly during their ascent and descent, causing them to increase in size.
  - Sleet: rain that freezes on its way to the ground.
  - Snow: water vapor converting directly to ice crystals.
  - Coalescence: raindrops growing larger as they collide

Water Cycle (Simple)

Evaporation (A): Liquid water turns into vapor.
Condensation (B): Water vapor turns back into liquid water.
Precipitation (C): Liquid or solid water falls from the clouds.
Runoff (D): Water flows over the ground.

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Description

Explore the essential components of air and the distinct layers of the atmosphere in this quiz. Understand the role of each gas in the air and the characteristics of the troposphere, stratosphere, mesosphere, and thermosphere. Test your knowledge on how these layers affect weather and climate.