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Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Neodymium is fairly common—about as common as cobalt, nickel, or copper—and is widely distributed in the Earth's crust. [10] Most of the world's commercial neodymium is mined in China, as is the case with many ...
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 ...
The human body tends to treat Rb + ions as if they were potassium ions, and therefore concentrates rubidium in the body's intracellular fluid (i.e., inside cells). [69] The ions are not particularly toxic; a 70 kg person contains on average 0.36 g of rubidium, and an increase in this value by 50 to 100 times did not show negative effects in ...
Perey discovered it as a decay product of 227 Ac. [184] Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well. [185]
2003: The Human Genome Project sequences the human genome with a 92% accuracy. [132] 2004: Ben Green and Terence Tao announce their proof on arithmetic progressions in prime numbers known as the Green–Tao Theorem. 2004: Andre Geim and Konstantin Novoselov isolated graphene, a monolayer of carbon atoms, and studied its quantum electrical ...
Rare earths were mainly discovered as components of minerals. The term "rare" refers to these rarely found minerals and "earth" comes from an old name for oxides, the chemical form for these elements in the mineral. [16]: 5 A mineral discovered by Lieutenant Carl Axel Arrhenius in 1787 at a quarry in the village of Ytterby, Sweden.
There is normally as little as 0.5 milligrams found within the entire human body; human breast milk contains 4 ppm. [82] Yttrium can be found in edible plants in concentrations between 20 ppm and 100 ppm (fresh weight), with cabbage having the largest amount. [82] With up to 700 ppm, the seeds of woody plants have the highest known concentrations.
Zinc has been found being used in impure forms in ancient times as well as in alloys such as brass that have been found to be over 2000 years old. [36] [37] Zinc was distinctly recognized as a metal under the designation of Fasada in the medical Lexicon ascribed to the Hindu king Madanapala (of Taka dynasty) and written about the year 1374. [38]