Earth's Atmosphere

Which of the following is one of the reasons why air density & air pressure decrease with increasing altitude?

• Air density & Air pressure decrease with increasing altitude due to that gravity forces the gases of the troposphere towards the center of the Earth. Thus, gas molecules will be greatest at seal level.
• Air density & Air pressure decrease with increasing altitude due to that the surface area of the Earth's atmosphere decreases with increasing altitude, thus gas molecules can spread out. 
• Air density & Air pressure increase with increasing altitude. So the following question is worded wrong.
• none of the answers are correct

The mesosphere is an important layer within the atmosphere because...

• this is the layer where weather occurs.

• this is the layer where the ozone layer is located, within which it absorbs UV radiation.

• this layer burns up the meteoroids that enter the Earth's mesosphere. This is due to the particles heating the objects as they enter the atmosphere.

• this is the layer where the space shuttle is located.

The result of the weight of a column of air pushing down on an area.

• air pressure
• altitude
• elevation

Condition of Earth's atmosphere at a particular time & place

• climate
• biogeography
• precipitation
• weather

Which list shows the regions of the atmosphere in order from Earth to space?

• thermosphere, mesosphere, stratosphere, troposphere
• mesosphere, stratosphere, troposphere, thermosphere
• troposphere, mesosphere, stratosphere, thermosphere
• troposphere, stratosphere, mesosphere, thermosphere

The ______ contains the ozone layer.

• troposphere

• mesosphere

• stratosphere

• exosphere

Reflection and absorption by the atmosphere prevent some _____ from reaching Earth's surface.

• ozone
• radiation
• nitrogen
• oxygen

In general, atmospheric pressure is greatest near Earth's surface and _____ as you move upward away from sea level.  

• decreases
• increases
• stays the same
• doubles

Atmosphere layers are distinguished by their _____ 

• composition
• temperature
• altitude
• all of the above

If the ozone layer disappeared, life on Earth would be exposed to ______ concentrations of ultraviolet radiation.  

• lower
• higher
• no change in 
• none of the above