enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Period (periodic table) - Wikipedia

    en.wikipedia.org/wiki/Period_(periodic_table)

    In the periodic table of the elements, each numbered row is a period. A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor.

  3. Octet rule - Wikipedia

    en.wikipedia.org/wiki/Octet_rule

    The bonding in carbon dioxide (CO 2): all atoms are surrounded by 8 electrons, fulfilling the octet rule.. The octet rule is a chemical rule of thumb that reflects the theory that main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

  4. Oxyanion - Wikipedia

    en.wikipedia.org/wiki/Oxyanion

    n, is dictated by the oxidation state of the element A and its position in the periodic table. Elements of the first row are limited to a maximum coordination number of 4. However, none of the first row elements has a monomeric oxyanion with that coordination number. Instead, carbonate (CO 2− 3) and nitrate (NO −

  5. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    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.

  6. Types of periodic tables - Wikipedia

    en.wikipedia.org/wiki/Types_of_periodic_tables

    A rendering of Bayley's periodic table of 1882 [25] A redrawn version of Kapustinsky's triangular or step pyramid periodic table (1953). [26] Period 0 includes the electron and neutron. Each period repeats once. Two kinds of bilateral symmetry are present: shape; and metals and nonmetals in each half.

  7. Periodic table (electron configurations) - Wikipedia

    en.wikipedia.org/wiki/Periodic_table_(electron...

    The construction of the periodic table ignores these irregularities and is based on ideal electron configurations. [2] Note the non-linear shell ordering, which comes about due to the different energies of smaller and larger shells.

  8. Chemical element - Wikipedia

    en.wikipedia.org/wiki/Chemical_element

    Much of the modern understanding of elements developed from the work of Dmitri Mendeleev, a Russian chemist who published the first recognizable periodic table in 1869. This table organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties ...

  9. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    118 chemical elements have been identified and named officially by IUPAC.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).