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Roman numerals: for example the word "six" in the clue might be used to indicate the letters VI; The name of a chemical element may be used to signify its symbol; e.g., W for tungsten; The days of the week; e.g., TH for Thursday; Country codes; e.g., "Switzerland" can indicate the letters CH; ICAO spelling alphabet: where Mike signifies M and ...
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 list of chemical elements named after places includes elements named both directly and indirectly for places. 41 of the 118 chemical elements have names associated with, or specifically named for, places around the world or among astronomical objects.
Carbon is the sixth element, with a ground-state electron configuration of 1s 2 2s 2 2p 2, of which the four outer electrons are valence electrons. Its first four ionisation energies, 1086.5, 2352.6, 4620.5 and 6222.7 kJ/mol, are much higher than those of the heavier group-14 elements.
Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only 222 Rn has a sufficiently long half-life (3.825 days) for it to be released from the soil and rock where it is generated.
Cerium is a chemical element; it has symbol Ce and atomic number 58. It is a soft , ductile , and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the oxidation state of +3 characteristic of the series, it also has a stable +4 state that does not oxidize water.
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
These elements have 6, 5, and 4 valence electrons, thus favoring +6, +5, and +4 oxidation states respectively, and display different physical and chemical properties. Thorium and protactinium, but not uranium compounds, are poorly soluble in aqueous solutions and precipitate into sediments; the precipitation rate is faster for thorium than for ...