Posted St. Valentine's Day, 2000 Modified: Dec 17, 2002 Robert Hedges
The table below gives the amount of each chemical element found in the human body, from most to least abundant. For each element, there is the amount in mass units in an averge (70-kilogram) person, the volume of the element, and the length of the side of a cube that would contain that amount of the pure element. Volumes of solid and liquid elements are based on density at or near room temperature (where available). For the gaseous elements (oxygen, hydrogen, nitrogen, chlorine, and fluorine), I chose to use the density of each in the liquid state at the respective boiling point.
Raw data from which this table was made are from Emsley, John, The Elements, 3rd ed., Clarendon Press, Oxford, 1998. This is a great trove of information, which I highly recommend for anyone wishing to learn more about the elements.
| Element | Mass of element in a 70-kg person |
Volume of purified element |
Element would comprise a cube this long on a side: |
| oxygen | 43 kg | 37 L | 33.5 cm |
| carbon | 16 kg | 7.08 L | 19.2 cm |
| hydrogen | 7 kg | 98.6 L | 46.2 cm |
| nitrogen | 1.8 kg | 2.05 L | 12.7 cm |
| calcium | 1.0 kg | 645 mL | 8.64 cm |
| phosphorus | 780 g | 429 mL | 7.54 cm |
| potassium | 140 g | 162 mL | 5.46 cm |
| sulfur | 140 g | 67.6 mL | 4.07 cm |
| sodium | 100 g | 103 mL | 4.69 cm |
| chlorine | 95 g | 63 mL | 3.98 cm |
| magnesium | 19 g | 10.9 mL | 2.22 cm |
| iron | 4.2 g | 0.53 mL | 8.1 mm |
| fluorine | 2.6 g | 1.72 mL | 1.20 cm |
| zinc | 2.3 g | 0.32 mL | 6.9 mm |
| silicon | 1.0 g | 0.43 mL | 7.5 mm |
| rubidium | 0.68 g | 0.44 mL | 7.6 mm |
| strontium | 0.32 g | 0.13 mL | 5.0 mm |
| bromine | 0.26 g | 64.2 µL | 4.0 mm |
| lead | 0.12 g | 10.6 µL | 2.2 mm |
| copper | 72 mg | 8.04 µL | 2.0 mm |
| aluminum | 60 mg | 22 µL | 2.8 mm |
| cadmium | 50 mg | 5.78 µL | 1.8 mm |
| cerium | 40 mg | 4.85 µL | 1.7 mm |
| barium | 22 mg | 6.12 µL | 1.8 mm |
| iodine | 20 mg | 4.06 µL | 1.6 mm |
| tin | 20 mg | 3.48 µL | 1.5 mm |
| titanium | 20 mg | 4.41 µL | 1.6 mm |
| boron | 18 mg | 7.69 µL | 2.0 mm |
| nickel | 15 mg | 1.69 µL | 1.2 mm |
| selenium | 15 mg | 3.13 µL | 1.5 mm |
| chromium | 14 mg | 1.95 µL | 1.3 mm |
| manganese | 12 mg | 1.61 µL | 1.2 mm |
| arsenic | 7 mg | 1.21 µL | 1.1 mm |
| lithium | 7 mg | 13.1 µL | 2.4 mm |
| cesium | 6 mg | 3.2 µL | 1.5 mm |
| mercury | 6 mg | 0.44 µL | 0.8 mm |
| germanium | 5 mg | 0.94 µL | 1.0 mm |
| molybdenum | 5 mg | 0.49 µL | 0.8 mm |
| cobalt | 3 mg | 0.34 µL | 0.7 mm |
| antimony | 2 mg | 0.30 µL | 0.7 mm |
| silver | 2 mg | 0.19 µL | 0.6 mm |
| niobium | 1.5 mg | 0.18 µL | 0.6 mm |
| zirconium | 1 mg | 0.15 µL | 0.54 mm |
| lanthanium | 0.8 mg | 0.13 µL | 0.51 mm |
| gallium | 0.7 mg | 0.12 µL | 0.49 mm |
| tellurium | 0.7 mg | 0.11 µL | 0.48 mm |
| yttrium | 0.6 mg | 0.13 µL | 0.51 mm |
| bismuth | 0.5 mg | 51 nL | 0.37 mm |
| thallium | 0.5 mg | 42 nL | 0.35 mm |
| indium | 0.4 mg | 55 nL | 0.38 mm |
| gold | 0.2 mg | 10 nL | 0.22 mm |
| scandium | 0.2 mg | 67 nL | 0.41 mm |
| tantalum | 0.2 mg | 12 nL | 0.23 mm |
| vanadium | 0.11 mg | 18 nL | 0.26 mm |
| thorium | 0.1 mg | 8.5 nL | 0.20 mm |
| uranium | 0.1 mg | 5.3 nL | 0.17 mm |
| samarium | 50 µg | 6.7 nL | 0.19 mm |
| beryllium | 36 µg | 20 nL | 0.27 mm |
| tungsten | 20 µg | 1.0 nL | 0.10 mm |
Oxygen is the most abundant element in the earth's crust and in the body. The body's 43 kilograms of oxygen is found mostly as a component of water, which makes up 70% of total body weight. Oxygen is also an integral component of all proteins, nucleic acids (DNA and RNA), carbohydrates, and fats.
Rubidium is the most abundant element in the body (0.68 g) that has no known biological role (silicon, which is slightly more abundant, may or may not have a metabolic function).
Vanadium is the body's least abundant element (0.11 mg) that has a known biologic role, followed by cobalt (3 mg), the latter being a constituent of vitamin B12.
The last of the body's elements to be discovered was fluorine, by Moissan in 1886.