Year 9 Unit 2 Test - Air

What is the chemical composition of air in the Earth's atmosphere?

• approximately 78 per cent nitrogen and 21 per cent oxygen

• approximately 60 per cent humidity and 20 per cent nitrogen

• approximately 21 per cent nitrogen and 78 per cent oxygen

What contributes to air pollution?

• car exhaust

• trees and plants

• power plants

Why is air pressure high at sea level?

• the whole atmosphere is pushing down on you

• it is not high at all

• because of the rain

Finish the sentence: When it ................. the humidity is at 100 per cent.

How do bioaerosols travel through the air?

• via wind

• via rain

• via a sneeze

• via airplanes

What causes poor air quality?

• forest fires

• heavy traffic

• too many flowers

• heavy rains

What is AQI?

• Air Quality Index

• Air Quality Incident

• Air pollution Quality Index

• Atmosphere Quality Ice

Match the sentences.

• using the AQI.

• Air can move

• fast and far.

• Humidity is usually measured in

• percentages.

• Air pollution is measured

• for living things.

• Carbon dioxide in the air

• can be both good and bad.

• Air is important

Reorder the following sentence:

• WHEN HUMANS AND ANIMALS BREATHE

• CALLED CARBON DIOXIDE

• THEY GIVE OFF AN ODOURLESS GAS

• OR CO2

Organize these options into the right categories:

Groups:

(a) What contributes to air pollution?

,

(b) What is the chemical composition of air?

• transportation

• 78 per cent nitrogen

• chemical products

• wildfires

• other gases

• 21 per cent oxygen