Atmosphere

How are the layers of the atmosphere classified?

• Density
• Gases
• Humidity
• Temperature

The order of the layers of the atmosphere from space to the earth's surface.

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

What percentage of the earth's atmosphere is oxygen?

• 78%
• 28%
• 71%
• 21%

What percentage of the earth's atmosphere is nitrogen?

• 78%
• 28%
• 71%
• 21%

Which atmospheric layer is the ozone layer found?

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere

As we go higher in  the atmosphere, the air pressure

• decreases
• increases
• does not change
• gets heavier

Why does air pressure differ around the earth?

• Cold air rises at the equator and warm air sinks at the poles.
• Cold air sinks at the equator and warm air rises at the poles.
• Warm air  air sinks at the equator and cold air rises at the poles.
• Warm air rises at the equator and cold air sinks at the poles.

Wind occurs because air usually moves from areas of high _______ to low _________

• pressure, pressure
• temperature, pressure
• pressure, temperature
• pressure, humidity

What causes winds to occur?

• Unequal distance
• Unequal humidity
• unequal heating
• unequal mass

Global winds happen 

• over a local area
• over a vast area including continents
• in the thermosphere
• in the mesosphere