Argon electronic structure

The electronic structure of the chlorine atom (3s-3p ) provides a satisfactory explanation of the elemental form of this substance also. The single half-filled 3p orbital can be used to form one covalent bond, and therefore chlorine exists as a diatomic molecule. Finally, in the argon atom all valence orbitals of low energy are occupied by electrons, and the possibility for chemical bonding between the atoms is lost. 

Parent NiNO and Ni(NO)2 have been prepared by cocondensation of Ni and NO in solid argon and investigated by IR spectroscopy in combination with DFT calculations.2434"2437 Two different isomeric forms have been evidenced for the dinitrosyl, Ni(r/1-NO)2 and Ni(r/2-NO)2, differing by their coordination modes and electronic structure.24 6... 

The elements helium, neon, argon, krypton, xenon, and radon—known as the noble gases—almost always have monatomic molecules. Their atoms are not combined with atoms of other elements or with other atoms like themselves. Prior to 1962, no compounds of these elements were known. (Since 1962, some compounds of krypton, xenon, and radon have been prepared.) Why are these elements so stable, while the elements with atomic numbers 1 less or 1 more are so reactive The answer lies in the electronic structures of their atoms. The electrons in atoms are arranged in shells, as described in Sec. 3.6. (A more detailed account of electronic structure will be presented in Chap. 17.)... 

The matrix IR spectra of la and several isotopomers (cU-la, l80-la) reveal details of the electronic structure of the carbene.23 In particular the red-shift of the C=0 stretching vibration (compared to p-benzoquinone) below 1500 cm-1 indicates a substantial contribution of the phenoxyl/phenyl resonance structure to the wave function of la. The C2V symmetry of the carbene was experimentally revealed by measuring the IR dichroism of partially oriented samples of matrix-isolated la. The orientation of la in an argon matrix was achieved by irradiation with linearly polarized light. 

Both theory and experiment indicate that the electronic structures of the noble gases [helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn)] are especially nonreactive these atoms are said to contain filled shells (Table 2.1). Much of the chemistry of the elements present in organic molecules is understandable in terms of a simple model describing the tendencies of the atoms to attain such filled-shell conditions by gaining, losing, or, most importantly, sharing electrons. 

Table 9.6 Electronic structure of helium, neon and argon.

The chemical and electrochemical characteristic properties of elements are determined by the electrons in the last outer shell. Elements with outer levels filled to completion, i. e. the rare gases (helium, neon, argon, crypton, xenon and radon), are noted for the great stability of their electronic structures atoms of such elements, known for their chemical inactivity, do not show any tendency to form molecules, neither in mutual bonds nor in bonds with other atoms. 

Covalent bonding usually occurs between the elements in the centre of the table, e.g. carbon, and hydrogen or those elements on the right-hand side of the table, e.g. oxygen, nitrogen or chlorine. In the following examples each element achieves the stable outer electron structure of helium, neon or argon. 

For oxygen the argon-like structure requires two electrons from each atom and the double bond formed is symbolized 0=0. For nitrogen we have ... 

The theory behind this behaviour is that elements with electronic structures close to those of inert (noble) gases lose or gain electrons to achieve a stable (inert) structure. In equation 2.4, sodium (Na Z = 11) loses one electron to attain the electronic structure of neon (Ne Z= 10), while chlorine (Cl Z = 17) gains one electron to attain the electronic structure of argon (Ar Z= 18). The compound NaCl is formed by the transfer of one electron from sodium to chlorine and the solid is bonded by the electrostatic attraction of the donated/received electron. The compound is electrically neutral. 

In this reaction, Na atoms lose one electron each to form Na+ ions, which contain only ten electrons, the same number as the preceding noble gas, neon. We say that sodium ions have the neon electronic structure Na+ is isoelectronic with Ne (Section 6-5). In contrast. Cl atoms gain one electron each to form Cl ions, which contain 18 electrons. This is the same number as the following noble gas, argon Cl is isoelectronic with Ar. These processes can be represented compactly as... 

DOS, Argon. Ar at. wt 39,948 at- no. 18. Three stable isotopes 36 (0.337%) 38 (0.063%) 40 (99.600%) artificial, radioactive isotopesr 33 35. 37 39 4] 42. Abundance in earth s crust 4 X 10 % concentration in the atmosphere 0.93% by vol cosmic abundance 1.5 X 10 atom M0 atoms of Si. Elemental, monoatomic, gaseous constituent Of air, discovered by Rayleigh and Ramsay in 1894. Although molecular ions, hydrates and cl at h rates of argon have been observed, it should be considered a noble , chemically inert gas, due to its electronic structure. The outer p subshell is entirely filled ls22s42p63s23p6. Obtained commercially... 

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