Question

when we hu, ns breathe, our lungs exchange oxygen molecules in the air for carbon dioxide molecule. we exhale (breathe out) less oxygen and more carbon dioxide. this exchange must take place on moist surfaces which are deep within our lungs. the surfaces are called membranes. we also exhale water in the form of small droplets.
wormformation
worms respire through their. a worm does not have lungs inside its body as we do. however, excha n en and carbon dioxide molecules across a worms skin is similar to the in our lungs. this is why a worms skin must be moist to allow it to. if a worms body dries out, it dies because it cannot respire.
directions
use the diagram to answer the questions.
key
= gas exchange
= oxygen molecule
= carbon dioxide molecule

1. how many molecules of oxygen are on the a side of the moist membrane?
2. how many molecules of oxygen are on the b side?
3. how many molecules of carbon dioxide are on the b side?
4. which side contains the most molecules of oxygen?
5. molecules can freely move across the membrane from a to b and b to a. when we and the worms \breathe\, molecules of one gas try to be equal in number on both sides of membrane or skin. in the diagram above, which way do the molecules move to make both sides equal? write answers below:

a. kind of molecule from a to b? how many?
b. kind of molecule from b to a? how many?
bonus activity pick out 5 words from wormformation. write their definitions using a dictio

Explanation:

Step1: Count oxygen molecules on A side

Count black dots (oxygen molecules) on A side. There are 13.

Step2: Count oxygen molecules on B side

Count black dots (oxygen molecules) on B side. There are 3.

Step3: Count carbon - dioxide molecules on B side

Count white circles (carbon - dioxide molecules) on B side. There are 6.

Step4: Compare oxygen molecule counts

Since 13 (A side) > 3 (B side), A side has more oxygen molecules.

Step5a: Determine molecule movement from A to B

For oxygen: (13 + 3) / 2=8. So from A to B: 13 - 8 = 5 oxygen molecules.

Step5b: Determine molecule movement from B to A

For carbon - dioxide: Let the number of carbon - dioxide molecules on both sides be equal. Total carbon - dioxide molecules: 4 (A side) + 6 (B side)=10. So 10 / 2 = 5. From B to A: 6 - 5=1 carbon - dioxide molecule.

Answer:

1. 13
2. 3
3. 6
4. A side
5. a. Oxygen molecule, 5; b. Carbon - dioxide molecule, 1