Atmospheric Pressure Science 10

Why Does Atmospheric Pressure Exist?  Because the air in the atmosphere is pulled toward the Earth by Gravity  Currently there is a column of air above you that extends approximately 180km up with a mass of about 10000kg

Why Doesn’t Atmospheric Pressure Only Push Down on Us?  Because a gas is free to move (fills space), while it is held to Earth by gravity, it also is free to move around objects and we can move through it  Therefore, when we raise our hand, we don’t have to lift 10000kg of air in order to do so

Air Pressure Decreases with Altitude  The further from the surface of the Earth, the less air that is above you so the air pressure is lower.  Plot the Altitude versus Pressure data in the following table Altitude (km) Pressure (kPa)

Atmospheric Composition  Nitrogen – 78%  Oxygen – 21%  Other – 1% Argon Carbon dioxide Neon Helium Methane Krypton Xenon Hydrogen Ozone

Chapter 13 Review  Complete Questions 1-15 and on page 450-1