The small capillaries in the lungs are in close contact with the alveoli. a red blood cell takes up oxygen during the 0.5 s that it squeezes through a capillary at the surface of an alveolus.

what is the diffusion time for oxygen across the 1-μm -thick membrane separating air from blood? assume that the diffusion coefficient for oxygen in tissue is 2×10−11m2/s. give your answer to 1 significant figure.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force