Question

A girl holds her breath for 30 seconds, breathes out, and then breathes in. Compared with the air she breathes out, the air she breathes in contains less

A) carbon dioxide and water vapour
B) nitrogen and water vapour.
C) oxygen and carbon dioxide.
D) oxygen and nitrogen.

Answer 1

Required Answer:-

A girl holds her breath for 30 seconds, breathes out, and then breathes in. Compared with the air she breathes out, the air she breathes in contains less:

A) carbon dioxide and water vapour ✓

B) nitrogen and water vapour.

C) oxygen and carbon dioxide.

D) oxygen and nitrogen$.$

Explanation:-

Breathing involves exchange of gases which is composed of air with variable composition of gases.

• In breathed in air, there is 21% of oxygen and breathed out air contains only 16% oxygen.

• In breathed in air, there is 0.04% of carbon dioxide and breadthed out air contains 4% carbon dioxide.

Hence, the relative amount of oxygen is less and carbon dioxide is more. As per the question, Compared with the air she breathes out, the air she breathes in contains less CO2 and water vapour.

Answer 2

Answer:

Required Answer :-

Option A

Explanation :-

When she hold her air then she didn't release any air so she didn't get Carbon Dioxide.

Now,

When she breath air only one time then the water vapour decreases

Hence :-

Option A

Know More :-

• Air is a mixture of gases.
• The gases mainly found in air are :-
• Oxygen => 21% (approx)
• Carbon dioxide => 0.04
• Nitrogen => 79%(approx)
• Dust etc. => 0.01 %