Oxygen is the element with the highest percentage by mass in the human body.
Oxygen makes up approximately 65% of a human's body mass. This is due to its presence in water (H₂O), which comprises a significant portion of the body, as well as its crucial role in organic molecules like proteins, carbohydrates, and fats.
Here's a breakdown of the major elements and their approximate percentages by mass in the human body:
| Element | Percentage by Mass |
|---|---|
| Oxygen | ~65% |
| Carbon | ~18% |
| Hydrogen | ~10% |
| Nitrogen | ~3% |
| Calcium | ~1.5% |
| Phosphorus | ~1% |
| Potassium | ~0.4% |
| Sulfur | ~0.3% |
| Sodium | ~0.2% |
| Chlorine | ~0.2% |
| Magnesium | ~0.1% |
| Trace Elements | <1% |
As shown, oxygen significantly outweighs the other elements in terms of its contribution to overall body mass. Its high abundance is vital for respiration, metabolism, and the structure of essential biomolecules.
