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"Axis of Upheaval" is a term coined in 2024 by Center for a New American Security foreign policy analysts Richard Fontaine and Andrea Kendall-Taylor and used by many foreign policy analysts, [1] [2] [3] military officials, [4] [5] and international groups [6] to describe the growing anti-Western collaboration between Russia, Iran, China and ...
The following list identifies in rank order the possible biological roles of the chemical elements, ranging from a score of 5 for elements essential to all living things, to a score of 1 for elements that have no known effects on living things. There are also letter scores for special functions of the elements.
Each chemical element has a unique atomic number (Z— for "Zahl", German for "number") representing the number of protons in its nucleus. [4] Each distinct atomic number therefore corresponds to a class of atom: these classes are called the chemical elements. [5] The chemical elements are what the periodic table classifies and organizes.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
This table lists only the occurrences in compounds and complexes, not pure elements in their standard state or allotropes. Noble gas +1 Bold values are main oxidation states
The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).
Edward Hitchcock's fold-out paleontological chart in his 1840 Elementary Geology. Although tree-like diagrams have long been used to organise knowledge, and although branching diagrams known as claves ("keys") were omnipresent in eighteenth-century natural history, it appears that the earliest tree diagram of natural order was the 1801 "Arbre botanique" (Botanical Tree) of the French ...
The position of the actinides is more questionable, but the most common and stable of them, thorium (Th) and uranium (U), are similar to main-group elements as thorium is an electropositive element with only one main oxidation state (+4), and uranium has two main ones separated by two oxidation units (+4 and +6). [3]