Electron inner

AES ARABS Auger electron spectroscopy [77, 112-114, 117] Angle-resolved AES [85, 115] An incident high-energy electron ejects an inner electron from an atom an outer electron (e.g., L) falls into the vacancy and the released energy is given to an ejected Auger electron Surface composition... 

The electron configuration is the orbital description of the locations of the electrons in an unexcited atom. Using principles of physics, chemists can predict how atoms will react based upon the electron configuration. They can predict properties such as stability, boiling point, and conductivity. Typically, only the outermost electron shells matter in chemistry, so we truncate the inner electron shell notation by replacing the long-hand orbital description with the symbol for a noble gas in brackets. This method of notation vastly simplifies the description for large molecules. 

When the hole in the /th shell is filled by an electron from theyth shell, there is a hole in the latter shell that will in turn be filled by an electron from a higher kth shell. This may result in the emission of a second x-ray, such that one hole in an inner electron shell can result in a cascade of several x-rays having ever-decreasing energies. 

Rumpf, m. body (of an en ne, etc.) core (of an atom or ion) trimk, torso hull (of a ship) (Aero.) fuselage, -elektron, n. inner electron (as distinguished from an optical or valence electron), -fl che, /. (Geol.) peneplain. -wirkung, /. (atomic) core effect. Rumsprit, m. double rum. 

It is possible to explain these trends in terms of the electron configurations of the corresponding atoms. Consider first the increase in radius observed as we move down the table, let us say among the alkali metals (Group 1). All these elements have a single s electron outside a filled level or filled p sublevel. Electrons in these inner levels are much closer to the nucleus than the outer s electron and hence effectively shield it from the positive charge of the nucleus. To a first approximation, each inner electron cancels the charge of one pro-... 

K. See Equilibrium constant Ka. See Acid equilibrium constant See Base equilibrium constant Kc. See Equilibrium constant Kf. See Formation equilibrium constant Kr See Equilibrium constant K,p. See Solubility product constant K . See Water ion product constant K-electron capture The natural radioactive process in which an inner electron (n = 1) enters the nucleus, converting a proton to a neutron, 514 Kelvin, Lord, 8... 

ELEMENT SYMBOL NUCLEAR CHARGE inner electrons valence electrons ionization ENERGY, El (kcal/mole)... 

In the preliminary discussions in the 1929 paper (Eq. 11), Hylleraas also discussed some lower approximations and pointed out the importance of a configuration where there exist one "inner electron and one "outer electron. In modern terminology, this corresponds to a splitting of the closed shell (Is)2 into an open shell (Is, Is), or to the use of "different orbitals for different electrons. Hylleraas reported the good result E = —2.8754 at.u. for such a configuration, but pointed also out that a "correlated wave function of the form... 

When multi-electron atoms are combined to form a chemical bond they do not utilize all of their electrons. In general, one can separate the electrons of a given atom into inner-shell core electrons and the valence electrons which are available for chemical bonding. For example, the carbon atom has six electrons, two occupy the inner Is orbital, while the remaining four occupy the 2s and three 2p orbitals. These four can participate in the formation of chemical bonds. It is common practice in semi-empirical quantum mechanics to consider only the outer valence electrons and orbitals in the calculations and to replace the inner electrons + nuclear core with a screened nuclear charge. Thus, for carbon, we would only consider the 2s and 2p orbitals and the four electrons that occupy them and the +6 nuclear charge would be replaced with a +4 screened nuclear charge. 

As a first approximation, each electron in a many-electron atom can be considered to have the distribution in space of a hydrogen-like electron under the action of the effective nuclear charge (Z—Ss)e, in which 5s represents the screening effect of inner electrons. In the course of a previous investigation,6 values of S5 for a large number of ions were derived. 

Bonds become weaker as we move down the periodic table. Compare C—O and C—S or the four carbon-halogen bonds. This is a consequence of the first generalization, since bond distances must increa.se as we go down the periodic table because the number of inner electrons increases. 

When an excited state is converted by ejection of an atomic electron, a high positive charge can be produced through subsequent Auger electron emission. Within the period of molecular vibration this charge is spread throughout the molecule to all atoms, and a Coulomb explosion results. This primary phenomenon occurs, of course, not only as a result of [ decay, but must be taken into account in all cases of nuclear reaction when deexcitation by inner electron conversion occurs... 

The results discussed in Sections 3.1-3.3 turned out as very valuable with respect to the knowledge about the transition from bulk metal to molecule. The most important method, however, to gain direct information from individual metal nanoparticles on their inner electronic life is the tunnelling spectroscopy. The method is based on the single-electron tunnelling (SET) through an intermediate island between two metal electrodes as is indicated in Figure 10. 

Electron dot diagrams use the chemical symbol to represent the nucleus plus the inner electrons and a dot to represent each valence electron. Such diagrams will be extremely useful in Chap. 5. 

The surface molecule model has been used to study chemisorption of hydrogen 47) and nitrogen 48) on tungsten (100). The parameters used in these calculations are collected in Table IV. Preliminary calculations on the diatomic molecules WH and WW showed that inclusion of tungsten 5 p orbitals is essential to produce a minimum in the energy/ distance curves. However, the repulsion due to inner electrons could be calculated by the empirical relationship ... 

Normally, in impact ionization, outer electrons are removed. Infrequently, however, an inner electron may be ejected or a K-process may occur such as an orbital electron capture or /3-decay. In such cases, the result is an electronic rearrangement, in preference to emission. Since enough energy is available, frequently the resultant ion is multiply charged. The cross section for this process follows the usual Bethe-type variation -T 1 ln(BT), where B is a constant (Fiquet-Fayard et al., 1968). In charged particle irradiation, the amount of energy lost in the K-processes is very small, usually much less than 1%. On the other hand, some specific effect may be attributable to that that is, experiments can be so designed. 

It is well known that y or X photons have energies suitable for excitation of inner electrons. We can use ultraviolet and visible radiation to initiate chemical reactions (photochemistry). Infrared radiation excites bond vibrations only whereas hyperfrequencies excite molecular rotation. In Tab. 1.1 the energies associated with chemical bonds and Brownian motion are compared with the microwave photon corresponding to the frequency used in microwave heating systems such as domestic and industrial ovens (2.45 GHz, 12.22 cm). 

As we move from left to right along a period, the outer shell electrons do experience a progressively stronger force of attraction to the nucleus due to the combination of an increase in the number of protons and a constant nuclear shielding by inner electrons. As a result the atomic radii decrease. 

As we move down a group, the outer electrons are partially shielded from the attractive force of the nucleus by an increasing number of inner electrons. This effect is partially responsible for the observed increase in atomic... 

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