Composition of Air

To which state of matter does air belong?

• solid

• liquid

• gas

Which statement about air is true?

• Air has a fixed shape

• Air takes the shape of its container

Air is classified as a__________.

• substance

• mixture

What is the chemical symbol for nitrogen?

How many atoms make up a molecule of carbon dioxide?

What is the chemical symbol for oxygen?

Which gas found in air is an important part of the process of photosynthesis?

• carbon dioxide

• oxygen

• nitrogen

• water vapor

This gas makes up 78% of air.

• carbon dioxide

• nitrogen

• oxygen

• water vapor

How many atoms make up a molecule of water?

This gas makes up 21% of air.

• carbon dioxide

• nitrogen

• oxygen

• water vapor