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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 periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.
Periodic table with elements colored according to the half-life of their most stable isotope. Of the elements with atomic numbers 1 to 92, most can be found in nature, having stable isotopes (such as oxygen) or very long-lived radioisotopes (such as uranium), or existing as common decay products of the decay of uranium and thorium (such as radon).
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. Except for the isotopes of hydrogen (which differ greatly from each other in relative mass—enough to cause chemical effects), the isotopes of a given ...
Chemical elements that are not synthesised; Classical element, the concept in ancient Greece of earth, water, air or fire; Natural abundance, the relative amounts of isotopes of a chemical element; Abundance of the chemical elements, the relative occurrence of chemical elements
An international committee decided in 1992 that the Berkeley and Dubna laboratories should share credit for the discovery. An element naming controversy erupted and as a result IUPAC adopted unnilhexium (Unh) as a temporary systematic element name. In 1994, a committee of IUPAC adopted a rule that no element can be named after a living person. [15]
Einsteinium is the element with the highest atomic number which has been observed in macroscopic quantities in its pure form as einsteinium-253. [4] Like all synthetic transuranium elements, isotopes of einsteinium are very radioactive and are considered highly dangerous to health on ingestion. [5]
41 of the 118 known elements have names associated with, or specifically named for, places around the world or among astronomical objects. 32 of these have names tied to the places on Earth, and the other nine are named after to Solar System objects: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium after their respective ...