Atmosphere and Air Pressure

The atmosphere is

• the layer in which weather occurs
• the layer that contains the ozone layer
• The layer of water in the oceans
• the layer of gases that surrounds Earth

What percent of our atmosphere is made up of gases other than oxygen?

• 5
• 1
• 10
• 2

Ozone is

• a form of oxygen with three oxygen atoms in each molecule
• a form of nitrogen with three nitrogen atoms in each molecule
• a form of oxygen with two oxygen atoms in each molecule
• a form of nitrogen with two nitrogen atoms in each molecule

Earth's atmosphere is important to living things because it

• contains dust and other particles
• is very thin compared to the size of Earth
• provides all the gases that living things need to survive.
• maintains a constant relative humidity

Earth's atmosphere traps energy form the sun, which

• allows water to exist as a liquid
• allows solar radiation to penetrate to the surface
• allows ozone to form easily
• causes meteor to burn up

Density can be determine by using the formula

• density = mass / volume
• density = volume/ mass
• density = mass ⋅ volume
• density = mass + volume

The less mass in a given volume of air, the 

• more the air weighs
• greater the air pressure
• more dense the air
• less dense the air

The air pressure acting on the roof of your house

• comes form the air within a few feet of your rooftop
• is much greater on top of the roof than below
• comes from all the air above your roof
• is much greater underneath your roof than on top of it

Instruments used to measure air pressure are called

• thermometers
• hygrometers
• hydrometers
• barometers

An aneroid barometer is different from a mercury barometer in that it

• measures temperature
• uses alcohol instead of mercury
• does not contain a liquid
• provides readings that increase as air pressure increases