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Actinium is a chemical element; it has symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium ...
The actinide series is a group of chemical elements with atomic numbers ranging from 89 to 102, [note 1] including notable elements such as uranium and plutonium.The nuclides (or isotopes) thorium-232, uranium-235, and uranium-238 occur primordially, while trace quantities of actinium, protactinium, neptunium, and plutonium exist as a result of radioactive decay and (in the case of neptunium ...
Three isotopes, 225 Ac, 227 Ac and 228 Ac, were found in nature and the others were produced in the laboratory; only the three natural isotopes are used in applications. Actinium-225 is a member of the radioactive neptunium series ; [ 60 ] it was first discovered in 1947 as a decay product of uranium-233 and it is an α-emitter with a half-life ...
Biological roles of the elements. A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]
Actinidine is an iridoid produced in nature by a wide variety of plants and animals. It was the first cyclopentanoid monoterpene alkaloid to be discovered. [2] It is one of several compounds that may be extracted from the valerian (Valeriana officinalis) root [3] and silver vine (Actinidia polygama), as well as several types of insects in the larval and imaginal stages. [4]
Actinide chemistry. Plutonium is a transuranic radioactive chemical element, an actinide metal. Actinide chemistry (or actinoid chemistry) is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium.
edit. Actinium (89 Ac) has no stable isotopes and no characteristic terrestrial isotopic composition, thus a standard atomic weight cannot be given. There are 34 known isotopes, from 203 Ac to 236 Ac, and 7 isomers. Three isotopes are found in nature, 225 Ac, 227 Ac and 228 Ac, as intermediate decay products of, respectively, 237 Np, 235 U, and ...
Molybdenum (Mo) is the most abundant transition element in solution in the sea (mostly as dianionic molybdate ion) and in living organisms, its abundance in the Earth's crust is quite low. Therefore, the use of Mo by living organisms seems surprising at first glance. Archaea, bacteria, fungi, plants, and animals, including humans, require ...