When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. History of the periodic table - Wikipedia

    en.wikipedia.org/wiki/History_of_the_periodic_table

    This is an accepted version of this page This is the latest accepted revision, reviewed on 29 September 2024. Development of the table of chemical elements The American chemist Glenn T. Seaborg —after whom the element seaborgium is named—standing in front of a periodic table, May 19, 1950 Part of a series on the Periodic table Periodic table forms 18-column 32-column Alternative and ...

  3. 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. It is a depiction of the periodic law, which states that when the elements are arranged in order ...

  4. Group (periodic table) - Wikipedia

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

    In the of the elements, each column is a group. In chemistry, a group (also known as a family) [1] is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the 14 f-block columns, between groups 2 and 3, are not numbered. The elements in a group have similar physical or chemical ...

  5. Atom - Wikipedia

    en.wikipedia.org/wiki/Atom

    Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium ...

  6. Fine structure - Wikipedia

    en.wikipedia.org/wiki/Fine_structure

    However, a more accurate model takes into account relativistic and spin effects, which break the degeneracy of the energy levels and split the spectral lines. The scale of the fine structure splitting relative to the gross structure energies is on the order of ( Zα ) 2 , where Z is the atomic number and α is the fine-structure constant , a ...

  7. Block (periodic table) - Wikipedia

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

    e. A block of the periodic table is a set of elements unified by the atomic orbitals their valence electrons or vacancies lie in. [1] The term seems to have been first used by Charles Janet. [2] Each block is named after its characteristic orbital: s-block, p-block, d-block, f-block and g-block. The block names (s, p, d, and f) are derived from ...

  8. Discovery of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Discovery_of_chemical_elements

    Nilson split Marignac's ytterbia into pure ytterbia and a new element that matched Mendeleev's 1871 predicted eka-boron. [141] 69 Thulium: 1879 T. Cleve 1879: T. Cleve: Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. [142] 62 Samarium: 1879 P.E.L. de Boisbaudran 1879: P.E.L. de Boisbaudran

  9. 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. Arranged this way, elements in the same group (column ...