Standard Science Primary 5 Systems

What happens to the air we breathe out compared to the air we breathe in?

A It is cooler.
B It contains more carbon dioxide and water vapour.
C It contains less nitrogen.
D It contains more oxygen.
Show Worked Solution

Worked Solution

Step 1: The body uses oxygen for respiration and produces carbon dioxide as waste. Step 2: Water vapour is also a byproduct of respiration. Step 3: Therefore, exhaled air has higher CO2 and water vapour content.

Correct answer: It contains more carbon dioxide and water vapour.

Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.

Start Free Trial — 7 Days Free