The concentration of psa (prostate-specific antigen) in the blood is sometimes used as a screening test for possible prostate cancer in men. the value is normally reported as the number of nanograms of psa per milliliter of blood. a psa of 1.6 ng/ml is considered low. express that value in terms of the units shown.

Cancer of the prostate is one of the most common types of cancer among American men. More than 6 in 10 cases of prostate cancer cases occur in men 65 and older. Treatment for prostate cancer works best when the disease is found early.

Explanation:

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.