enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Yttrium - Wikipedia

    en.wikipedia.org/wiki/Yttrium

    About 31 ppm of the Earth's crust is yttrium, [9] making it the 43rd most abundant element. [51]: 615 Yttrium is found in soil in concentrations between 10 and 150 ppm (dry weight average of 23 ppm) and in sea water at 9 ppt. [51] Lunar rock samples collected during the American Apollo Project have a relatively high content of yttrium. [46]

  3. Electron configuration - Wikipedia

    en.wikipedia.org/wiki/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 1s 2 2s 2 2p 6 , meaning that the 1s, 2s, and 2p subshells are occupied by two, two, and six ...

  4. Bohr–Sommerfeld model - Wikipedia

    en.wikipedia.org/wiki/Bohr–Sommerfeld_model

    Orbitals of the Radium. (End plates to [1]) 5 electrons with the same principal and auxiliary quantum numbers, orbiting in sync. ([2] page 364) The Sommerfeld extensions of the 1913 solar system Bohr model of the hydrogen atom showing the addition of elliptical orbits to explain spectral fine structure.

  5. Crystal structure - Wikipedia

    en.wikipedia.org/wiki/Crystal_structure

    The crystallographic point group or crystal class is the mathematical group comprising the symmetry operations that leave at least one point unmoved and that leave the appearance of the crystal structure unchanged. These symmetry operations include Reflection, which reflects the structure across a reflection plane

  6. Bohr model - Wikipedia

    en.wikipedia.org/wiki/Bohr_model

    When Bohr began his work on a new atomic theory in the summer of 1912 [8]: 237 the atomic model proposed by J. J. Thomson, now known as the plum pudding model, was the best available. [9]: 37 Thomson proposed a model with electrons rotating in coplanar rings within an atomic-sized, positively-charged, spherical volume. Thomson showed that this ...

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

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

    Atomic Spectroscopy, by W.C. Martin and W.L. Wiese in Atomic, Molecular, & Optical Physics Handbook, ed. by G.W.F. Drake (AIP, Woodbury, NY, 1996) Chapter 10, pp. 135–153. This website is also cited in the CRC Handbook as source of Section 1, subsection Electron Configuration of Neutral Atoms in the Ground State.

  8. Atomic packing factor - Wikipedia

    en.wikipedia.org/wiki/Atomic_packing_factor

    In crystallography, atomic packing factor (APF), packing efficiency, or packing fraction is the fraction of volume in a crystal structure that is occupied by constituent particles. It is a dimensionless quantity and always less than unity. In atomic systems, by convention, the APF is determined by assuming that atoms are rigid spheres. The ...

  9. Walsh diagram - Wikipedia

    en.wikipedia.org/wiki/Walsh_diagram

    Walsh Diagram of an HAH molecule. Walsh diagrams, often called angular coordinate diagrams or correlation diagrams, are representations of calculated orbital binding energies of a molecule versus a distortion coordinate (bond angles), used for making quick predictions about the geometries of small molecules.