Question: What Are the Elements in the Human Body?
Answer: Most of the human body is made up of water, H2O, with cells consisting of 65-90% water by weight. Therefore, it isn't surprising that most of a human body's mass is oxygen. Carbon, the basic unit for organic molecules, comes in second. 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. You may also wish to view the element composition of an average human body by mass.
- Oxygen (65%)
- Carbon (18%)
- Hydrogen (10%)
- Nitrogen (3%)
- Calcium (1.5%)
- Phosphorus (1.0%)
- Potassium (0.35%)
- Sulfur (0.25%)
- Sodium (0.15%)
- Magnesium (0.05%)
- Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)
- Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)
Reference: H. A. Harper, V. W. Rodwell, P. A. Mayes, Review of Physiological Chemistry, 16th ed., Lange Medical Publications, Los Altos, California 1977.
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