Properties of Air
How many properties does air have?
3
What is a mercury barometer?
instrument that measures air pressure using liquid mercury
the reading is in inches
What is altitude (or elevation)?
the distance above sea level
Why aren't you crushed by all the weight in the air?
The pressure is all around us in different directions
What three properties does air have?
mass
density
volume
What is an aneroid barometer?
instrument with thin walls and no liquid
uses dials with a needle that points at the number for the air pressure
Air pressure decreases as altitude ___.
If the air pressure goes up, what happens to our straw on our homemade barometers?
High pressure pushes on the balloon and makes the straw go up
Air pressure is the result of the _____ of a column of air pushing ____ on an area.
Air pressure is the result of the WEIGHT of a column of air pushing DOWN on an area.
The greater the air pressure, the ___ the reading is in inches.
The greater the air pressure, the HIGHER the reading is in inches.
As air pressure decreases, so does _____.
density
Why is it harder to breathe at the top of a mountain?
The oxygen in the air is less dense.
Is air heavy?
Yes! The weight of a column of air on you is about the same weight as a large school bus.
Sometimes air pressure measurement is in ____ instead of inches.
millibars
Air at the top of the mountain or high in the atmosphere has ___ weight pressing on it.
less
What are the three properties of air?
mass
density
volume
What is mass, density, and volume?
The three properties of air
- mass (amount of matter in an object)
- density (the amount of mass in a given volume of air)
- volume (the amount of space an object takes up)
The lower the air pressure, the ___ the reading is in inches
lower
The amount of oxygen is 21% at sea level and on a mountain. The air is less dense at a high altitude, so there are ____ oxygen molecules in the air.
fewer
How can you measure air pressure?
barometeres