Question

gas exchange
the table shows what happens
to the air we inhale.

1. what gas is removed from inhaled air?
2. what gases are added to inhaled air and then exhaled? and
3. which gas shows the greatest difference in percent between inhaled and

exhaled air?

Explanation:

Step1: Analyze gas removal

Compare inhaled and exhaled percentages. Oxygen's percentage decreases from $20.71\%$ (inhaled) to $14.6\%$ (exhaled), so it is removed.

Step2: Analyze gas addition

Carbon dioxide's percentage increases from $0.04\%$ (inhaled) to $4.0\%$ (exhaled), and water's percentage increases from $1.25\%$ (inhaled) to $5.9\%$ (exhaled). So these two gases are added.

Step3: Calculate percentage differences

For oxygen: $|20.71 - 14.6|=6.11$. For carbon dioxide: $|4.0 - 0.04| = 3.96$. For water: $|5.9 - 1.25|=4.65$. Since $6.11>4.65>3.96$, oxygen shows the greatest difference.

Answer:

1. Oxygen ($O_2$)
2. Carbon dioxide ($CO_2$) and water ($H_2O$)
3. Oxygen ($O_2$)