Oxygen atom, energy level diagram

Fig. 2-17.—Energy-level diagram for the neutral oxygen atom.

The following molecular orbital energy-level diagram shows the energies and electron occupancies of the MOs derived from the atomic 2p orbitals for an oxygen-containing binary compound of potassium. 

Draw MO energy-level diagrams for O2,O2-, and O22-, including only MOs derived from the oxygen 2p atomic orbitals. Show the electron population of the MOs. (See Section 7.14.)... 

The procedure for calculating energy level diagrams by the self-consistent field Xa scattered wave (SCF-Xa-SW) method is as follows (Sherman, 1984, 1991). An octahedral cluster such as [FeO6]10 is partitioned into a set of (overlapping) spheres centred about divalent iron and each oxygen atom, and these are surrounded by an outer sphere. Within each atomic sphere the one-electron Schrodinger equation... 

Atomic orbital energy level diagrams. To simplify these diagrams, the orbitals are shown at the same energies for different atoms. Actually, the energy of an orbital decreases as the number of protons in the atom increases.Thus the Ip orbitals of fluorine are lower in energy than the Ip orbitals of oxygen. 

Hund s rule states that the electrons within a given subshell remain as unpaired as possible. Moreover, if there are two or more unpaired electrons in a given subshell, they all must occupy different orbitals and have the same electron spin (all arrows representing unpaired electrons in a subshell point up or all point down). The energy level diagrams for the carbon, nitrogen, and oxygen atoms illustrate these rules ... 

The energy level diagrams show one unpaired electron in a fluorine atom, two in an oxygen atom, and one in a boron atom. 

Fig. 4.27. Molecular-orbital energy-level diagram for the (FeO,) " cluster calculated using the MS-SCF-Jfa method. The highest-energy occupied orbital is the 2 2g i containing one electron. Also shown are the energies of Fe and O atomic orbitals. Spin-up (f ) and spin-down ( i ) molecular orbitals are shown in this spin-unrestricted calculation on a regular octahedral (O ) cluster at an iron-oxygen distance of 2.17 A (after Tossell et al., 1974 reproduced with the publisher s permission).

In terms of this model, two effective pairs around an atom will always require sp hybridization of that atom. The sp orbitals of carbon in carbon dioxide are shown in Fig. 14.15, and the corresponding orbital energy-level diagram for their formation is given in Fig. 14.16. The sp hybrid orbitals are used to form the a bonds between carbon and the oxygen atoms. Note that two 2p orbitals remain unchanged on the sp hybridized carbon. They are used to form the it bonds to the oxygen atoms. 

Using a MO energy-level diagram, would you expect 02 to have a lower or higher first ionization energy than atomic oxygen Why ... 

Molecular orbital theory then explains why NO is stable with respect to N and O atoms, and predicts that NO+ will form fairly easily. We have not explained why nitric oxide gas consists of NO molecules rather than N202 molecules, or why NO is unstable with respect to oxidation by oxygen to N02. To do this, we would have to consider orbital energy-level diagrams for N202 or N02 and 02 as well. 

Originai atomic orbitais Fig. Energy level diagram for sp hybridised oxygen. 

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