Composition of Inhaled and Exhaled Air

What is the percentage of nitrogen (N₂) in both inhaled and exhaled air?

• 21%

• 79%

• 4%

• 0.04%

Which gas increases in percentage from inhaled air to exhaled air?

• Oxygen

• Nitrogen

• Carbon dioxide

• Helium

What is the percentage of oxygen (O₂) in inhaled air?

• 21%

• 79%

• 4%

• 0.04%

What is the percentage of carbon dioxide (CO₂) in exhaled air?

• 0.04%

• 4%

• 21%

• 79%

Which gas remains at the same percentage in both inhaled and exhaled air?

• Oxygen

• Nitrogen

• Carbon dioxide

• Hydrogen

How does the percentage of oxygen change from inhaled air to exhaled air?

• It increases

• It decreases

• It stays the same

• It disappears

What is the percentage of carbon dioxide (CO₂) in inhaled air?

• 4%

• 21%

• 0.04%

• 79%

If a student breathes in air, which gas is present in the largest amount?

• Oxygen

• Nitrogen

• Carbon dioxide

• Hydrogen

Compare the percentage of oxygen in exhaled air to that in inhaled air.

• It is higher in exhaled air

• It is lower in exhaled air

• It is the same in both

• There is no oxygen in exhaled air

Which of the following statements is true about the composition of exhaled air?

• Exhaled air contains more oxygen than inhaled air.

• Exhaled air contains less carbon dioxide than inhaled air.

• Exhaled air contains the same amount of nitrogen as inhaled air.

• Exhaled air contains no nitrogen.