1.the less mass in a given volume of air, the

more dense the air

less dense the air

more the air weighs

greater the air pressure

2.
carbon dioxide makes up of earth’s atmosphere.

less than 1%

between 5% and 10%

more than 10%

about 3%

3.
the two most abundant gases in the atmosphere are

carbon dioxide and oxygen

nitrogen and hydrogen

carbon dioxide and nitrogen

nitrogen and oxygen

4.
what is true about the air pressure acting on the roof of your house?

it is much greater on top of the roof than below it.

it comes from the air within a few feet of your rooftop.

it comes from the column of air above your roof.

it is much greater underneath your roof than on top of it.

5.
what is the first layer of atmosphere an astronaut passes through during reentry from space?

stratosphere

ionosphere

exosphere

mesosphere