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Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
These five elements have a strong affinity for sulfur; in the human body they usually bind, via thiol groups (–SH), to enzymes responsible for controlling the speed of metabolic reactions. The resulting sulfur-metal bonds inhibit the proper functioning of the enzymes involved; human health deteriorates, sometimes fatally. [ 56 ]
Selenium, which is an essential element for animals and prokaryotes and is a beneficial element for many plants, is the least-common of all the elements essential to life. [ 3 ] [ 63 ] Selenium acts as the catalytic center of several antioxidant enzymes, such as glutathione peroxidase , [ 11 ] and plays a wide variety of other biological roles .
Livermorium is projected to be the fourth member of the 7p series of chemical elements and the heaviest member of group 16 in the periodic table, below polonium. While it is the least theoretically studied of the 7p elements, its chemistry is expected to be quite similar to that of polonium. [4]
Trace metals within the human body include iron, lithium, zinc, copper, chromium, nickel, cobalt, vanadium, molybdenum, manganese and others. [ 1 ] [ 2 ] [ 3 ] Some of the trace metals are needed by living organisms to function properly and are depleted through the expenditure of energy by various metabolic processes of living organisms.
Tungsten (also called wolfram) [14] [15] is a chemical element; it has symbol W and atomic number 74. It is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a distinct element in 1781 and first isolated as a metal in 1783.
Plutonium is an element in which the 5f electrons are the transition border between delocalized and localized; it is therefore considered one of the most complex elements. [46] The anomalous behavior of plutonium is caused by its electronic structure.
Its prevalence in the human body—at an adult average of 120 mg [t] —is nevertheless exceeded only by zinc (2500 mg) and iron (4000 mg) among the heavy metals. [259] Lead salts are very efficiently absorbed by the body. [260] A small amount of lead (1%) is stored in bones; the rest is excreted in urine and feces within a few weeks of exposure.