Standard Science Primary 5 Systems

What is the main difference between the air we inhale and the air we exhale?

A Exhaled air contains more nitrogen.
B Inhaled air contains more carbon dioxide.
C Inhaled air contains less oxygen.
D Exhaled air contains more water vapor and carbon dioxide.
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Worked Solution

Step 1: During respiration, the body takes in oxygen and produces carbon dioxide and water vapor. Step 2: Exhaled air is warmer and contains more waste products of respiration. Step 3: Therefore, exhaled air has higher CO2 and water vapor levels.

Correct answer: Exhaled air contains more water vapor and carbon dioxide.

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