Air Composition and Pressure

In what direction(s) does air exert pressure?

• downward
• no direction
• upward
• all directions

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

• air pressure
• density
• mass
• volume
  none of the above

A _____________ is the scientific  instrument used to measure air pressure.

• anemometer
• barometer
• thermometer
• watch

What happens to the amount of oxygen molecules as altitude increases?

• There are fewer oxygen molecules
• There are more oxygen molecules
• There are the same amount of molecules
• Nothing happens to the amount of molecules

Michael observes the air pressure daily. Over the last couple of days, the air pressure has been dropping (getting lower). What weather will Michael most likely observe as a result?

• increasingly clear skies and more wind
• increasingly clear skies and dry weather
• increasingly cloudy skies and possible storms
• increasingly cloudy skies and cooler temperatures

78% of earth's atmosphere is composed of ______________.

• methane
• oxygen
• argon
• nitrogen

Cold air exerts _____________ pressure than warm air.

• the same
• greater
• less
• more variable

When going up a mountain, your ears 'pop' because the air pressure __________________________.

• remains the same 
• decreases 
• increases 
• becomes constant

Air pressure does not crush objects on earth _________.

• because more air pushes up than down
• because gravity keeps air pressure away
• because air pressure pushes in all directions
• because the Earth has an opposing force of gravity

The amount of mass in a unit volume of a substance is the _____.

• mass
• pressure
• volume
• density