What is name of the proces ehich oxygen move across the wall of the alveolus?

The process by which oxygen moves across the wall of the alveolus is called diffusion. During diffusion, oxygen molecules move from an area of higher concentration in the alveoli to an area of lower concentration in the surrounding capillaries. This process is essential for gas exchange in the lungs, allowing oxygen to enter the bloodstream while carbon dioxide is expelled from the blood into the alveoli.