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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 ...
The naming rules promulgated by IUPAC in 2002 declared that all newly discovered elements should have names ending in -ium, for linguistic consistency. [40] In 2016, this was amended so that elements in the halogen and noble gas groups would receive the traditional -ine and -on suffixes. This amendment was put into practice for tennessine ...
Transactinide elements – Elements after the actinides (atomic number greater than 103). Transplutonium elements – Elements with atomic number greater than 94. Transuranium elements – Elements with atomic number greater than 92. Valve metal - a metal which, in an electrolytic cell, passes current in only one direction.
Traditionally the suffix -ium was used only for metals (or at least elements that were expected to be metallic), and other elements used different suffixes: halogens used -ine and noble gases used -on instead. However, the systematic names use -ium for all elements regardless of group.
All elements have multiple isotopes, variants with the same number of protons but different numbers of neutrons. For example, carbon has three naturally occurring isotopes: all of its atoms have six protons and most have six neutrons as well, but about one per cent have seven neutrons, and a very small fraction have eight neutrons. Isotopes are ...
Since the mass numbers of these are 12, 13 and 14 respectively, said three isotopes are known as carbon-12, carbon-13, and carbon-14 (12 C, 13 C, and 14 C). Natural carbon is a mixture of 12 C (about 98.9%), 13 C (about 1.1%) and about 1 atom per trillion of 14 C. Most (54 of 94) naturally occurring elements have more than one stable isotope.
Period 5 has the same number of elements as period 4 and follows the same general structure but with one more post transition metal and one fewer nonmetal. Of the three heaviest elements with biological roles, two ( molybdenum and iodine ) are in this period; tungsten , in period 6, is heavier, along with several of the early lanthanides .
Indium is one of three known elements (the others being tellurium and rhenium) of which the stable isotope is less abundant in nature than the long-lived primordial radioisotopes. [ 37 ] The stablest artificial isotope is indium-111 , with a half-life of approximately 2.8 days.