he diagram shows an alveolus and blood capillary.The arrows show the direct of movement of oxygen and carbon dioxide.By which process does carbon dioxide move?

The process by which carbon dioxide moves from the alveolus to the blood capillary is called diffusion. Here are the steps:

1. Carbon dioxide is produced as a waste product in the body's cells during respiration, a process in which oxygen is used to produce energy from glucose.

2. This carbon dioxide is then transported via the bloodstream to the lungs, where it enters the tiny air sacs known as alveoli.

3. In the alveoli, carbon dioxide is in higher concentration in the blood than in the air within the alveoli.

4. Due to this concentration gradient, carbon dioxide diffuses out of the blood (where it's in high concentration) into the alveoli (where it's in low concentration).

5. From the alveoli, the carbon dioxide is exhaled out of the body.

This process of moving from an area of high concentration to an area of low concentration is known as diffusion.