By mass, most of human body is composed of nitrogen, carbon,oxygen, or hydrogen.?

Answer 1

As the predominant component of the human body is water and as oxygen is the heaviest of the elements you ask about then logically it must be ...OXYGEN!

Answer 2

Carbon. Everything (organic) has carbon in it.

Edit:

Actually, i did some research on this question because i read some other answers and it is not carbon. The body is composed of around 72% water (probably more) and water is approximately 88.89% oxygen, so therefore the body should be mostly OXYGEN. Here is a list of percentages i found online.

By Weight

Oxygen 65%
Carbon 18%
Hydrogen 10%
Nitrogen 3%
Calcium 1.5%
Phosphorous 1.0%
Potassium 0.35%
Sulfur 0.25%
Sodium 0.15%
Chlorine 0.15%
Magnesium 0.05%
Iron 0.0004%
Iodine 0.00004%

Answer 3

OXYGEN because the adult human is about 60% water or H20. But oxygen is heavier than hydrogen, another element in water, so by mass, oxygen occupies most of the human body.

Answer 4

Oxygen. Not just the human body but all living beings, the earth's crust and the earth's oceans. But not the mantle, core or atmosphere.

Answer 5

Carbon