Bond Energies, Valence State Energies And Resonance¹,² (open access)

Bond Energies, Valence State Energies And Resonance¹,²

Previous attempts to interpret chemical structure in terms of x-electron resonance have been recently criticized. A reinterpretation of the lengths of the C-C bonds in terms of orbital radii has not revealed any effects of x-electron resonance in the ground states of classical molecules such as 1, 3-butadiene, methyl acetylene, etc. Even in a non-classical molecule such as benzene, resonance shortening of the CC bond is only in terms of the strengths of the hybrid orbitals. If the lengths and force constants of the C-C bonds vary with hybridization, so also must their bond energies. If resonance is not important in classical molecules, the heat of atomization of a classical molecule must be given by the sum of either the energies of the bonds or the contributions of the atoms present in it. To test this theory, we have estimated the contributions of some standard carbon atoms, viz., primary, secondary, tertiary, quaternary, trigonal, and diagonal carbon atoms.
Date: February 1961
Creator: Somayajulu, G. R.
System: The UNT Digital Library
The Infrared Spectra Of Marginally Metallic Systems, Sodium-Ammonia Solutions (open access)

The Infrared Spectra Of Marginally Metallic Systems, Sodium-Ammonia Solutions

The sodium-ammonia solution system permits investigation of an array of compositions spanning the transition from non-metallic to metallic bonding. Reflection spectra in the range 1-20 [ ] were measured for solutions of mole ratio 5.5 to 168 [ ] per Na. The dilute solutions show peaks characteristic of the vibrations of ammonia and a strong peak near 1.5 [ ] which is assigned to the solvated [ ] species. Concentrated solutions show high reflectivity over broad wavelength ranges. The results for nearly saturated solutions are fitted reasonably by the free electron model, but in the range of mole ratio 10-15 a complex array of energy absorption processes of finite frequencies are required to fit the spectra.
Date: February 1961
Creator: Beckman, Tad A., 1936- & Pitzer, Kenneth S. (Kenneth Sanborn), 1914-1997
System: The UNT Digital Library
Bremsstrahlung (open access)

Bremsstrahlung

An electron can suffer a very large acceleration in passing through the Coulomb field of a nucleus, and in this interaction the radiant energy (photons) lost by the electrons is called bremsstrahlung (also, bremsstrahlung sometimes designates the interaction itself). If an electron whose total energy [formula] traverses matter of atomic number Z, the electron loses energy chiefly by bremsstrahlung. This case is considered here.
Date: February 1961
Creator: Kenney, R. W.
System: The UNT Digital Library
Effects Of A Magnetic Field On Natural Convection In A Toroidal Channel (open access)

Effects Of A Magnetic Field On Natural Convection In A Toroidal Channel

The problem of the natural convection of an electrically and thermally conducting fluid within a long, narrow, vertical toroidal channel centered in a large block of an electrically and thermally conducting solid is analyzed. A uniform horizontal magnetic field is applied to the fluid, and the bottom of the solid block is maintained at a higher fixed temperature than the top. The laminar steady-state single-cell convective motion of the fluid is considered and an approximate solution is found for the heat transfer rate between the bottom and top surfaces of the block in the limiting cases of small and large Hartmann number. A numerical example is given for liquid sodium in which the application of a magnetic field of a few hundred gauss is shown to significantly reduce the rate of heat transfer.
Date: February 1961
Creator: Concus, Paul
System: The UNT Digital Library
Orbital Radii, Bond Length And Resonance (open access)

Orbital Radii, Bond Length And Resonance

The radius of a c-p hybrid orbital has been found to be given by the expression: [formula] where A is the radius of the pure p orbital, B, a universal constant equal to 0.336 A, and [ ], the coefficient of mixing in the hybrid s + [ ]. When radii appropriate for the orbitals that are paired together are used, bond length is additive of the orbital radii and no Schomaker-Stevenson correction is necessary. This shows that most bonds can be treated as covalent, single and localized.
Date: February 1961
Creator: Somayajulu, G. R.
System: The UNT Digital Library
Kinematics And Dispersion Relations For General Production Processes (open access)

Kinematics And Dispersion Relations For General Production Processes

The method of dispersion relations has in recent years found a wide application for the study of elementary particle reactions. Most of the work, however, deals with reactions of the type [formula], while the theory of those with more than two particles in the final state is still in a very preliminary stage. One reason for this is that even with only three particles in the final state the theory is already much more complicated. Nevertheless, a further development of the theory seemed to us very desirable. The theory at present is being developed on various levels simultaneously. Generally speaking, the aim of this paper is to put the theory in a form as closely as possible analogous to Mandelstam's formulation of the theory of reactions of type [formula]. In the later sections we specialize on reactions [formula], but as much as possible the formulation is in more general terms.
Date: February 2, 1961
Creator: Kretzschmar, Martin
System: The UNT Digital Library
A Partially Degenerate, Relativistic, Ideal Electron Gas (open access)

A Partially Degenerate, Relativistic, Ideal Electron Gas

Tables of the electron pressure and kinetic energy for a partially degenerate, relativistic, ideal electron gas are computed by numerical integration using an IBM 7090 electronic calculator. These are given in terms of log10(B) and log10(0), where B is the ratio of the temperature to the rest mass of the electron and (O) is proportional to the numerical density of electrons. The tables include values of T from 5 million to 400 billion degrees and cover the range of electron densities from the region of a perfect gas to the region of complete degeneracy.
Date: February 23, 1961
Creator: Grasberger, William H.
System: The UNT Digital Library