The element present in the highest proportion (about 65% by mass) in the human body is:

Question

Ortho-sulphobenzimide is used as:

Answer 1

Think of the body as mostly water plus organic tissue.

Water is about 60 to 65 percent of body weight, and in water ($H_2O$), oxygen alone accounts for 8 out of every 9 grams, since oxygen has mass 16 out of the 18 gram molar mass of water.
This is why oxygen, not hydrogen, dominates the elemental mass even though water has twice as many hydrogen atoms as oxygen atoms.
Adding the oxygen present in proteins, sugars, fats and bone phosphates pushes the total oxygen content of the body to roughly 65 percent by mass.
Carbon (about 18 percent) and hydrogen (about 10 percent) follow, with nitrogen and other elements making up the small remainder.
So the correct choice is oxygen, option C.

Answer 2

Think of the body as mostly water plus organic tissue.

Water is about 60 to 65 percent of body weight, and in water ($H_2O$), oxygen alone accounts for 8 out of every 9 grams, since oxygen has mass 16 out of the 18 gram molar mass of water.
This is why oxygen, not hydrogen, dominates the elemental mass even though water has twice as many hydrogen atoms as oxygen atoms.
Adding the oxygen present in proteins, sugars, fats and bone phosphates pushes the total oxygen content of the body to roughly 65 percent by mass.
Carbon (about 18 percent) and hydrogen (about 10 percent) follow, with nitrogen and other elements making up the small remainder.
So the correct choice is oxygen, option C.

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