II The small capillaries in the lungs are in close contact with the alveoli. A red blood cell takes up oxygen during the 0.5s that it squeezes through a capillary at the surface of an alveolus. What is the diffusion time for oxygen across the 1-um thick membrane separating air from blood? Assume that the diffusion coefficient for oxygen in tissue is .2x10^-11m^2/s Give your answer to 1 significant figure.
