Within the capillaries of the lungs, gases are exchanged by diffusion; oxygen diffuses from the to the and carbon dioxide diffuses from the to

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

multiplying and dividing the two decimals and the eqations by the same number of the overalls