Second-period elements, homonuclear diatomic molecules

Homonuclear diatomic molecules of second-period elements B2, C2, and N2 ... 

Homonuclear Diatomic Molecules of the Second Short Period Elements, E ... 

The electronic configurations of the homonuclear diatomic molecules of the elements of the second period, and some of their ions, are given in Table 4.1. 

Other than oxygen, O2, which homonuclear diatomic molecule(s) of second period elements should be paramagnetic Ans. Boron, B2... 

Assuming the elements in the second period can form homonuclear diatomic molecules, which diatomic molecules should have zero bond order ... 

The experimental data for homonuclear diatomic molecules arc summarized in Table XXX and Figure /, where it is seen that amongst elements of the second period there is a progressive change in the values of the dissociation energy, ue. the bond energy, and the... 

Figure 9-5 shows molecular orbital energy level diagrams for homonuclear diatomic molecules of elements in the first and second periods. Each diagram is an extension of the... 

HOMONUCLEAR DIATOMIC MOLECULES OF SECOND-PERIOD ELEMENTS... 

We are now ready to study the ground-state electron configuration of molecules containing second-period elements. We will consider only the simplest case, that of homonuclear diatomic molecules, or diatomic molecules containing atoms of the same elements. 

Homonuclear Diatomic Molecules of Second-Period Elements... 

We therefore proceed directly to the homonuclear diatomic molecule, X2, in which X represents a second-period element like oxygen or nitrogen. These molecules are not only interesting in themselves, but provide a natural bridge to linear polyatomic organic molecules like acetylene and, from there, to ethylene and beyond. 

Just as we treated the bonding in H2 by using molecular orbital theory, we can consider the MO description of otiier diatomic molecules. Initially we will restrict our discussion to homonuclear diatomic molecules (those composed of two identical atoms) of elements in flie second row of the periodic table. As we will see, die procedure for determining the distribution of electrons in these molecules closely follows the one we used for H2. 

The validity of molecular orbital theory is supported by its ability, unlike valence bond theory, to correctly predict certain properties of homonuclear diatomic molecules of elements in the first and second periods. What prediction would valence bond theory make about the paramagnetism of these molecules For which molecules does molecular orbital theory make a different prediction ... 

A A For which of the homonuclear diatomic molecules or ions of elements in the first and second periods would the paramagnetism or the bond order actually be different if the incorrect energy level diagram (Figure 9-5a vs. Figure 9-5 b) were used (Hint There are four or more correct answers.)... 

Figure 10.34 shows the relative energies of the molecular orbitals obtained from 2s and 2p atomic orbitals. This order of molecular orbitals reproduces the known electron configurations of homonuclear diatomic molecules composed of elements in the second row of the periodic table. The order of filling is... 

Homonuclear diatomic molecules (molecules made up of two atoms of the same kind) formed from second-period elements have between 2 and 16 valence electrons. To explain bonding in these molecules, we must consider the next set of higher energy molecular orbitals, which can be approximated by linear combinations of the valence atomic orbitals of the period 2 elements. 

Here is how we assign electrons to the molecular orbitals of the diatomic molecules of the second-period elements We start with the and a g orbitals filled. Then we add electrons, in order of increasing energy, to the available molecular orbitals of the second principal shell. Figure 11-26 shows the electron assignments for the homonuclear diatomic molecules of the second-period elements. Some molecular properties are also listed in the figure. 

The next homonuclear molecule composed of second row elements is B2, which has six total valence electrons to accommodate. We can approximate the next higher energy molecular orbitals for B2 and the rest of the period 2 diatomic molecules as linear... 

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