Atomic ions physics

Moseley J T 1984 Determination of ion molecular potential curves using photodissociative processes Applied Atomic Collision Physics ed H S W Massey, E W McDaniel and B Bederson (New York Academic)... 

Chantry P J 1982 Negative ion formation in gas lasers Applied Atomic Collision Physics Vol 3, Gas Lasers ed FI S W Massey, E W MoDaniel, B Bederson and W L Nighan (New York Aoademio)... 

McDaniel E W and McDowell M R C (eds) 1972 Case Studies in Atomic Coiiision Physics (Amsterdam North-Holland) vol 2 McDaniel E W, i rmak V, Dalgarno A, Ferguson E E and Friedman L (eds) 1970 ion-Moiecuie Reactions (New York Wiley) Bates D R (ed) 1962 Afom/c and Moiecuiar Processes (New York Academic)... 

The picture of a very dilute solution that we must adopt is shown schematically in Fig 2 Each ion is enclosed in its own co-sphere, while the remainder of the solvent between the ions docs not differ in any way from ordinary pure solvent. As a result of recent progress in atomic physics, we now know in great detail the structure and properties of different species of atomic ions in a vacuum and at the same time we know the physical properties of the pure solvent. In order to understand the properties of a very dilute solution, we need to discuss the portions of solvent that lie in the co-spheres of the ions. 

A diagram similar to Fig. 27c enables us to attach a definite physical meaning to the dissociation of a molecular ion, such as (PbCl)+ into a pair of atomic ions. 

Like diamond, DLC can be obtained by CVD by plasma action in a hydrocarbon atmosphere. Its deposition process differs from that of diamond in as much as the activation is not so much chemical (i.e., the use of hydrogen atoms) but physical. This physical activation is usually obtained by colliding accelerated ions produced by a high-frequency discharge. 

When students do make an attempt to relate between the three levels of representation, several unexpected trends in their reasoning are revealed. In the majority of explanations given by students about chemical reactions in a review imdertaken by Andersson (1986), there was a clear extrapolation of physical attributes and changes from the macroscopic world to the particle or submicroscopic one. So, when wood bums, wood molecules are also said to bum. If metallic copper is bright reddish-brown, atoms of copper are also imagined to be reddish-brown in colour (Ben-Zvi, Eylon, Silberstein, 1986). One reason for such extrapolation of physical attributes of substances to the particulate level is the tendency of students to assume that the atoms, ions and molecules in a substance are veiy small portions of the continuous substance. 

A considerable body of scientific work has been accomplished in the past to define and characterize point defects. One major reason is that sometimes, the energy of a point defect can be calculated. In others, the charge-compensation within the solid becomes apparent. In many cases, if one deliberately adds an Impurity to a compound to modify its physical properties, the charge-compensation, intrinsic to the defect formed, can be predicted. We are now ready to describe these defects in terms of their energy and to present equations describing their equilibria. One way to do this is to use a "Plane-Net". This is simply a two-dimensional representation which uses symbols to replace the spherical images that we used above to represent the atoms (ions) in the structure. 

Kello, V., Urban, M. and Sadlej, A.J. (1996) Electric dipole polarizabilities of negative ions of the coinage metal atoms. Chemical Physics Letters, 253, 383-389. 

Single atomic ions confined in radio frequency traps and cooled by laser beams (Figure 7.4a) formed the basis for the first proposal of a CNOT quantum gate with an explicit physical system [14]. The first experimental realization of a CNOT quantum gate was in fact demonstrated on a system inspired by this scheme [37]. In this proposal, two internal electronic states of alkaline-earth or transition metal ions (e.g. Ba2+ or Yb3+) define the qubit basis. These states have excellent coherence properties, with T2 and T2 in the range of seconds [15]. Each qubit can be... 

As was discussed in Chapter 6, the electronic polarizability, a, of species is very useful for correlating many chemical and physical properties. Values of a are usually expressed in cm3 per unit (atom, ion, or molecule). Because atomic dimensions are conveniently expressed in angstroms, the polarizability is also expressed as A3, so lCT24cm3 = 1 A3. The polarizability gives a measure of the ability of the electron cloud of a species to be distorted so it is also related to the hard-soft character of the species in a qualitative way. Table 9.6 gives the polarizabilities for ions and molecules. 

The electric mass filter is the basis for the electrodynamic trap used for studies of the spectroscopy of atomic ions that earned Paul and Dehmelt the 1989 Nobel Prize in Physics. A wide variety of electrode configurations can be used to trap particles, and a particularly simple design was proposed by Straubel (1956). His dc electrodes were flat plates, and the ac electrode was a simple torus or washer placed at the midplane between the endplates. 

This review of the chemistry and physics of microparticles and their characterization is by no means comprehensive, for the very large range of masses that can be studied with the electrodynamic balance makes it possible to explore the spectroscopy of atomic ions. This field is a large one, and Nobel laureates Hans Dehmelt and Wolfgang Paul have labored long in that fruitful scientific garden. The application of particle levitation to atmospheric aerosols, to studies of Knudsen aerosol phenomena, and to heat and mass transfer in the free-molecule regime would require as much space as this survey. 

Calculated from Ionization potentials of atoms and atomic ions in the CRC Handbook of Chemistry and Physics [8] Conversion factor 1 hartree = 27.2114 eV... 

Figure 11.16 Atomic number (Z) distributions for the low-energy fission of several actinide nuclei are shown in each panel. (From K.-H. Schmidt et al., in Heavy Ion Physics, Y. T. Oganessiam and R. Kalpakchieva, Eds. Copyright 1998 World Scientific. Reprinted by permission of World Scientific.)...

Following the direction established by its predecessor, this second volume of The Excited State in Chemical Physics further summarizes theoretical and experimental information available from a variety of sources. It deals with the production of excited atoms, ions, and molecules the elastic and inelastic scattering of these species and the production of excited products following collision. 

The basic energy level diagram was developed at the dawn of quantum physics to explain the absorption and emission characteristics of simple atoms, ions and molecules found in the sun and laboratory flames. 

Most of the universe is composed of plasma, a state of matter that exists at incredibly high temperatures (>5000°C). Under normal conditions, matter on Earth can only exist in the other three physical states, namely, the solid, liquid, or gaseous states. As you learned in an earlier course, the particle theory describes matter in all states as being composed of tiny invisible particles, which can be atoms, ions, or molecules. In this section, you will learn how these particles behave in each state. You will also learn about the forces that cause their behaviour. 

For the chemical physicist the rapid growth of studies associated with the formation and destruction of excited atoms, ions, and molecules has created an awkward situation. Much of the literature lies buried in many unexpected places and is very difficult to locate. Furthermore, when and if it is reviewed, it has largely been prepared for specialist groups such as those interested in lasers, biophysics, chemical kinetics, or perhaps the physics and chemistry of the atmosphere. Consequently the nonspecialist and to a large extent even the specialist in one of the above-mentioned areas finds it difficult to keep reasonably in touch with the various aspects of excited-state research. 

Governed by the nature of the surface species, diffusion may be categorized as diffusion of physically adsorbed molecules and of chemisorbed species, and self-diffusion. The latter refers to the diffusion of atoms, ions, and clusters on the surface of their own crystal lattices and has been studied mostly for metals. All three categories of surface diffusion are of importance in catalysis. A review concerning all categories is available [20]. 

Sputtering. Sputtering is a purely physical process with a yield (atom ion-1) given by the relation Y,A sfE, — V-Fih) with , > Eth, 20-50 eV [68] for clean surfaces. 

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