What element makes up the most in the human body by mass?

The human body is composed, primarily, of very few elements. In fact, only 4 elements make up the 96% of our body. These elements are oxygen, carbon, hydrogen and nitrogen. Rest about 4% is made up of other elements, including, calcium, potassium, phosphorus, sulfur, etc. Oxygen makes up almost 65% of our body mass, while carbon contributes about 18% of our body mass. Hydrogen is responsible for 10% and nitrogen makes up about 3% of our body mass. This is not difficult to understand, since our body is mostly made up of water (H2O). Thus, a person weighing 70 kg is composed of 45.5 kg oxygen, 12.6 kg carbon, 7 kg hydrogen and 2.1 kg nitrogen, while the rest of the body mass is made up by other elements.

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