Earth's Atmosphere: Composition and Layers

Which gas makes up the majority of Earth’s atmosphere?

• Nitrogen

• Oxygen

• Argon

• Carbon Dioxide

Which is NOT a reason that Earth’s atmosphere is important?

• It protects living things from ultraviolet radiation

• It burns up meteoroids which keeps them from hitting Earth

• It increases acid rain production
• It keeps Earth’s surface a comfortable temperature and helps water to remain a liquid

Compounds in Earth’s atmosphere can change with time and location.

• True

• False

Which layer of Earth’s atmosphere protects Earth’s surface from meteors?

• Mesosphere

• Stratosphere

• Troposphere

• Thermosphere

This layer blends in with outer space.

• Troposphere

• Mesosphere

• Exosphere
• Thermosphere

This layer protects living things from UV radiation.

• Troposphere

• Mesosphere

• Thermosphere

• Stratosphere

Which layer contains the Aurora Borealis?

• Troposphere

• Mesosphere

• Thermosphere
• Stratosphere

______ The outermost layer of the thermosphere where artificial spacecraft and unmanned satellites are found is called the -

• Troposphere

• Exosphere

• Ionosphere

• Mesosphere

______ In the troposphere, as altitude increases, pressure –

• decreases

• Increases

• Stays the same

______ In the thermosphere, as altitude increases, temperature –

• Decreases

• Increases

• Stays the same