Air has weight and exerts pressure when contained.
Air weighs more than five quadrillion tons, but yet we can't see, smell,
or feel it. Air is a powerful force on Earth exerting pressure on all
organisms. Even when you take a breath of air into your lungs, you are
changing the pressure. When you blow in air, you increase the molecules
of gas; when you blow, you decrease the pressure. The pressure inside
your body actually prevents the atmospheric pressure from
squishing you. However, if we visited Jupiter, the surface pressure
would squish us like a bug.
Astronauts that go into space or divers that go
under the ocean must take pressurized air with them. If we climb
a mountain that is too high, the air becomes less and less breathable.
The downward force exerted by overlying air causes greater pressure at
the bottom of the atmosphere. Air molecules are actually
"squeezed" by the weight of the air above. The pressure is
measured as101,325 Pascals which is called 1 atmosphere of pressure on
the surface of the Earth. We can live at 1 atmosphere, but once it gets
below (outer space) or higher (under the ocean) we have to create
pressurized cabins to keep our pressure at 1 atmosphere, so we donít