When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Selenium - Wikipedia

    en.wikipedia.org/wiki/Selenium

    Electron configuration 3d 10 4s 2 4p 4: Electrons per shell: 2, 8, 18, 6: Physical properties; ... Selenium is a chemical element; it has the symbol Se and atomic ...

  3. Aufbau principle - Wikipedia

    en.wikipedia.org/wiki/Aufbau_principle

    The rule then predicts the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 3d 9 4s 2, abbreviated [Ar] 3d 9 4s 2 where [Ar] denotes the configuration of argon, the preceding noble gas. However, the measured electron configuration of the copper atom is [Ar] 3d 10 4s 1. By filling the 3d subshell, copper can be in a lower energy state.

  4. Electron configurations of the elements (data page) - Wikipedia

    en.wikipedia.org/wiki/Electron_configurations_of...

    This page shows the electron configurations of the neutral gaseous atoms in their ground states. For each atom the subshells are given first in concise form, then with all subshells written out, followed by the number of electrons per shell. For phosphorus (element 15) as an example, the concise form is [Ne] 3s 2 3p 3.

  5. Electron shell - Wikipedia

    en.wikipedia.org/wiki/Electron_shell

    Electron shell. In chemistry and atomic physics, an electron shell may be thought of as an orbit that electrons follow around an atom 's nucleus. The closest shell to the nucleus is called the "1 shell" (also called the "K shell"), followed by the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), and so on further and further from ...

  6. Properties of nonmetals (and metalloids) by group - Wikipedia

    en.wikipedia.org/wiki/Properties_of_nonmetals...

    Selenium has a hexagonal polyatomic (CN 2) crystalline structure. It is a semiconductor with a band gap of 1.7 eV, and a photoconductor meaning its electrical conductivity increases a million-fold when illuminated. Selenium has a moderate ionisation energy (941.0 kJ/mol), high electron affinity (195 kJ/mol), and high electronegativity (2.55).

  7. Electron configuration - Wikipedia

    en.wikipedia.org/wiki/Electron_configuration

    Electron configuration. In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. [1] For example, the electron configuration of the neon atom is 1s2 2s2 2p6, meaning that the 1s, 2s, and 2p subshells are occupied by ...

  8. Selenium dioxide - Wikipedia

    en.wikipedia.org/wiki/Selenium_dioxide

    Solid SeO 2 is a one-dimensional polymer, the chain consisting of alternating selenium and oxygen atoms. Each Se atom is pyramidal and bears a terminal oxide group. The bridging Se-O bond lengths are 179 pm and the terminal Se-O distance is 162 pm. [5] The relative stereochemistry at Se alternates along the polymer chain (syndiotactic).

  9. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    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 ...