Valence-shell configurations

Antimony [7440-36-0] is the fourth member of the nitrogen family and has a valence shell configuration of The utilisation of these orbitals and, in... 

Each of the following valence-shell configurations is possible for a neutral atom for a certain element. What is the element and which configuration represents the ground state ... 

Give the notation for the valence-shell configuration (including the outermost (/-electrons) of (a) the alkali metals ... 

The octet rule tells us that eight electrons fill the outer shell of an atom to give a noble-gas ns1ns(l valence-shell configuration. However, when the central atom in a molecule has empty d-orbitals, it may be able to accommodate 10, 12, or even more electrons. The electrons in such an expanded valence shell may be present as lone pairs or may be used by the central atom to form additional bonds. 

A proton achieves the valence shell configuration of helium carbocations achieve the valence shell configuration of neon. 

Photoelectron spectra of ZnF2 in the vapour phase have been recorded using pseudomolecu-lar beam techniques, and it is proposed that the valence shell configuration is ... 

The valence-shell configuration of nitrogen is 2s22px12p),12p.1. The electronic configuration of potassium is ls22s22p63s23p64s1. 

Sharing of one or more valence electrons between two atoms allows each to possess a noble gas (s2p6) valence shell configuration. 

Elements with a valence-shell configuration 5, such as beryllium and mug nesium, might be expected to have completely filled bands and thus behave as nonmetals. However, the nearby /i-orbitals likewise form a band which overlaps the upper part of the 5-band to give a continuous conduction band with an abundance of unoccupied orbitals. Transition metals can also contribute their cf-orbitals to the conduction bands. Fig. 12.6 is a detailed plot of the band structure of metallic sodium, which shows how combinations of s, p and d energy bands can overlap. 

The most stable [U02(L)n] complexes are those, in which U atoms form stable 18-electron valence shell configurations. 

Table 2.7 also shows how the generation of subshells, s- p-, d- and /-orbitals, results in the build-up to the valence shell configuration of an atom as each n-value generates n — 1 /-values, each /-value 21 + Im, values, and each nii value two values of j. This build-up process then generates the increasing capacity of the K, L, M, and N shells for... 

Each block has a distinctly different chemistry, and within each block there is a more subtle variation of the chemistry depending on the valence shell electron configuration. Figure 3.3 shows an abbreviated form of the Periodic Table, Groups I-VIII, with the valence shell configurations, shown as Lewis dot structures, to emphasise the vertical... 

Figure 3.3 Abbreviated Periodic Table, valence shell configuration, dot form...

The number of electrons lost or gained is controlled by the valence shell configuration to form the next nearest inert gas core, thus ... 

To date, the emphasis has been on the formation of ionic cations or anions, by the formation of inert gas core configurations, which then combine to form purely electrostatic bonds, e.g. Na CP. An alternative type of bond is the covalent bond, which is characterised by the sharing of two electrons by two atoms, in a way that completes the inert gas core of both atoms. Thus, in the case of two hydrogen atoms, both with the same valence shell configuration, ls the formation of a homonuclear diatomic molecule of H2 can be represented, as follows ... 

In this way, the valence shell configuration of the central atom, combined with the Lewis representation of the inert gas shell, gives a very useful way of visualising the distribution of the valence shell electrons in this chemical book-keeping exercise. In these Lewis structures all the electrons are equivalent and the dot or cross notation simply indicates the source of the electrons from the central atom or the terminal atoms. 

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