Composition of Air--grade 5

What is the percentage composition of nitrogen in air?

• 78%

• 75%

• 86%

The composition of air consists of __________ key components.

• seven

• three

• ten

__________________ is the most important gas in the composition of air.

• Nitrogen

• Argon

• Oxygen

______________ is a combustible ( able to catch fire/ burn easily )gas.

• Nitrogen

• Oxygen

• Argon

_______________ is one of the most abundantly found gases on earth.

• Oxygen

• Carbon dioxide

• Nitrogen

Air is a

• mixture

• not a mixture

• none

Argon is used in _______________.

• Bulbs

• fluorescent tubes

• Both

Plants use ________________ for photosynthesis.

• Chlorine

• Nitrogen

• Carbon dioxide

Plants give out ________during photosynthesis.

• nitrogen

• oxygen

• carbon dioxide

Used in fire extinguisher .

• oxygen

• carbon -dioxide

• none