17.1 Atmosphere Characteristics

In which direction does Earth's axis currently point?

• toward Vega

• 23.5 degrees North

• toward the North Star

• to the right

How does weather differ from climate?

• Climate is constantly changing

• weather is consistent year after year

• weather is constantly changing

• weather is "average climate"

Which two gases make up 99% of the volume of clean dry air?

• oxygen and carbon dioxide

• nitrogen and ozone

• oxygen and nitrogen

• nitrogen and carbon dioxide

The amount of water vapor in the air varies from ...

• 0 to 4 %

• 5 to 10 %

• 10 - 25%

• 25 - 50%

What do water vapor and carbon dioxide have in common?

• they are atmospheric gases

• they are greenhouse gases

• they absorb heat

• all of these

The form of oxygen that combines three oxygen atoms per molecule (O3).

• oxygen ions

• ozone

• O2

• all of these

In which layers of the atmosphere does temperature increase with increasing height?

• troposphere and stratosphere

• stratosphere and mesosphere

• stratosphere and thermosphere

• troposphere and thermosphere

How do ozone molecules form in the stratosphere?

• a single atom of oxygen and an oxygen molecule collide

• through a process known as nuclear fusion

• through a process known as nuclear fission

• they are created by ultraviolet light from the sun

What are secondary pollutants?

• formed in the atmosphere by reactions among primary pollutants

• formed from the burning of fossil fuels

• formed from acid rain

• emissions and transportation vehicles

How much of Earth's atmosphere is located below about 5.6 kilograms?

• all of it

• 10%

• 25%

• 50%