In the lungs the movement of carbon dioxide out of the cells and oxygen into cells can best be explained by processes?

The movement of carbon dioxide out of the cells and oxygen into the cells in the lungs can be best explained by the processes of diffusion and partial pressure gradients. Oxygen, which has a higher partial pressure in the alveoli than in the blood, diffuses into the bloodstream, while carbon dioxide, having a higher partial pressure in the blood than in the alveoli, diffuses out into the air for exhalation. This exchange occurs in the alveoli, where the thin walls facilitate rapid gas exchange.