When.com Web Search

Search results

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

    en.wikipedia.org/wiki/Oxygen

    Oxygen is the most abundant chemical element by mass in the Earth's biosphere, air, sea and land. Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun's mass is oxygen. [19]

  3. Molecular orbital diagram - Wikipedia

    en.wikipedia.org/wiki/Molecular_orbital_diagram

    2 ion is formed with bond order 1/2. Another molecule that is precluded based on this principle is diberyllium. Beryllium has an electron configuration 1s 2 2s 2, so there are again two electrons in the valence level. However, the 2s can mix with the 2p orbitals in diberyllium, whereas there are no p orbitals in the valence level of hydrogen or ...

  4. Allotropes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Allotropes_of_oxygen

    Singlet oxygen is the common name used for the two metastable states of molecular oxygen (O 2) with higher energy than the ground state triplet oxygen. Because of the differences in their electron shells, singlet oxygen has different chemical and physical properties than triplet oxygen, including absorbing and emitting light at different ...

  5. Singlet oxygen - Wikipedia

    en.wikipedia.org/wiki/Singlet_oxygen

    The lowest excited state of the diatomic oxygen molecule is a singlet state. It is a gas with physical properties differing only subtly from those of the more prevalent triplet ground state of O 2. In terms of its chemical reactivity, however, singlet oxygen is far more reactive toward organic compounds.

  6. Molecular orbital - Wikipedia

    en.wikipedia.org/wiki/Molecular_orbital

    The advantage of this approach is that the orbitals will correspond more closely to the "bonds" of a molecule as depicted by a Lewis structure. As a disadvantage, the energy levels of these localized orbitals no longer have physical meaning. (The discussion in the rest of this article will focus on canonical molecular orbitals.

  7. Dioxygenyl - Wikipedia

    en.wikipedia.org/wiki/Dioxygenyl

    The dioxygenyl ion, O + 2, is a rarely-encountered oxycation in which both oxygen atoms have a formal oxidation state of + ⁠ 1 / 2 ⁠. It is formally derived from oxygen by the removal of an electron: O 2 → O + 2 + e −. The energy change for this process is called the ionization energy of the oxygen molecule.

  8. Energy level - Wikipedia

    en.wikipedia.org/wiki/Energy_level

    Roughly speaking, a molecular energy state (i.e., an eigenstate of the molecular Hamiltonian) is the sum of the electronic, vibrational, rotational, nuclear, and translational components, such that: = + + + + where E electronic is an eigenvalue of the electronic molecular Hamiltonian (the value of the potential energy surface) at the ...

  9. Triplet oxygen - Wikipedia

    en.wikipedia.org/wiki/Triplet_oxygen

    Under a molecular orbital theory framework, the oxygen-oxygen bond in triplet dioxygen is better described as one full σ bond plus two π half-bonds, each half-bond accounted for by two-center three-electron (2c-3e) bonding, to give a net bond order of two (1+2× ⁠ 1 / 2 ⁠), while also accounting for the spin state (S = 1).