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  2. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    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 ...

  3. Atomicity (database systems) - Wikipedia

    en.wikipedia.org/wiki/Atomicity_(database_systems)

    Atomicity does not behave completely orthogonally with regard to the other ACID properties of transactions. For example, isolation relies on atomicity to roll back the enclosing transaction in the event of an isolation violation such as a deadlock; consistency also relies on atomicity to roll back the enclosing transaction in the event of a consistency violation by an illegal transaction.

  4. Roles of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Roles_of_chemical_elements

    See also: Carbon-based life: Fossil fuels: coal, methane and petroleum Textile industry: cellulose Metallurgy: alloys, especially carbon steel 7: N: Nitrogen 2: 15: Bacteria and archaea: nitrogen fixation by diazotrophs All forms of life on Earth: essential component of amino acids and of nucleic acids Earth's atmosphere, soil, and life forms ...

  5. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    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.

  6. List of elements by atomic properties - Wikipedia

    en.wikipedia.org/wiki/List_of_elements_by_atomic...

    This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.

  7. ACID - Wikipedia

    en.wikipedia.org/wiki/ACID

    Alternatively, we may say that a logical transaction may be composed of several physical transactions. Unless and until all component physical transactions are executed, the logical transaction will not have occurred. An example of an atomic transaction is a monetary transfer from bank account A to account B.

  8. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    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 ...

  9. List of particles - Wikipedia

    en.wikipedia.org/wiki/List_of_particles

    An atom consists of a small, heavy nucleus surrounded by a relatively large, light cloud of electrons. An atomic nucleus consists of 1 or more protons and 0 or more neutrons. Protons and neutrons are, in turn, made of quarks. Each type of atom corresponds to a specific chemical element. To date, 118 elements have been discovered or created.