Neon Noble gases

Whether an element is the source of the cation or anion in an ionic bond depends on several factors for which the periodic table can serve as a guide In forming ionic compounds elements at the left of the periodic table typically lose electrons giving a cation that has the same electron configuration as the nearest noble gas Loss of an elec tron from sodium for example yields Na which has the same electron configuration as neon... 

Covalent bonding in F2 gives each fluonne eight electrons in its valence shell and a stable electron configuration equivalent to that of the noble gas neon... 

The number of covalent bonds an atom forms depends on how many additional valence electrons it needs to reach a noble-gas configuration. Hydrogen has one valence electron (Is) and needs one more to reach the helium configuration (Is2), so it forms one bond. Carbon has four valence electrons (2s2 2p2) and needs four more to reach the neon configuration (2s2 2p6), so it forms four bonds. Nitrogen has five valence electrons (2s2 2p3), needs three more, and forms three bonds oxygen has six valence electrons (2s2 2p4), needs two more, and forms two bonds and the halogens have seven valence electrons, need one more, and form one bond. 

As pointed out in Chapter 2, elements close to a noble gas in the periodic table form ions that have the same number of electrons as the noble-gas atom. This means that these ions have noble-gas electron configurations. Thus the three elements preceding neon (N, O, and F) and the three elements following neon (Na, Mg, and Al) all form ions with the neon configuration, is22s22p6. The three nonmetal atoms achieve this structure by gaining electrons to form anions ... 

As you can see, the fluorine atom owns six valence electrons outright and shares two others. Putting it another way, the F atom is surrounded by eight valence electrons its electron configuration has become ls22s22p6, which is that of the noble gas neon. This, according to Lewis, explains why the HF molecule is stable in contrast to species such as H2F, H3F,... none of which exist. 

As indicated in Fig. 21.3, for both atomic absorption spectroscopy and atomic fluorescence spectroscopy a resonance line source is required, and the most important of these is the hollow cathode lamp which is shown diagrammatically in Fig. 21.8. For any given determination the hollow cathode lamp used has an emitting cathode of the same element as that being studied in the flame. The cathode is in the form of a cylinder, and the electrodes are enclosed in a borosilicate or quartz envelope which contains an inert gas (neon or argon) at a pressure of approximately 5 torr. The application of a high potential across the electrodes causes a discharge which creates ions of the noble gas. These ions are accelerated to the cathode and, on collision, excite the cathode element to emission. Multi-element lamps are available in which the cathodes are made from alloys, but in these lamps the resonance line intensities of individual elements are somewhat reduced. 

The pattern of ion formation by main-group dements can be summarized by a single rule for atoms toward the left or right of the periodic table, atoms lose or gain electrons until they have the same number of electrons as the nearest noble-gas atom. Thus, magnesium loses two electrons and becomes Mg2+, which has the same number of electrons as an atom of neon. Selenium gains two electrons and becomes Se2+, which has the same number of electrons as krypton. 

FIGURE 15.25 The colors of this fluorescent lighting art hv Tom vnl noble-gas atoms. Neon is responsible for the red light i > li... 

B In fluorine (Group 17), an additional electron fills the single vacancy in the valence shell the shell now has the noble-gas configuration of neon and is complete. In neon, an additional electron would have to enter a new shell, where it would be farther from the attraction of the nucleus. 

Frenking G, Cremer D (1990) The Chemistry of the Nobles Gas Elements Helium, Neon, and Argon - Experimental Facts and Theoretical Predictions. 73 17-96 Frey M (1998) Nickel-Iron Hydrogenases Structural and Functional Properties. 90 97-126 Fricke B (1975) Superheavy Elements. 21 89-144... 

The description of the first 10 electrons in the configuration of aluminum is identical to that of neon, so we can represent that portion as [Ne]. With this notation, the configuration of A1 becomes [Ne] 3 5" 3 p The element at the end of each row of the periodic table has a noble gas configuration. These configurations can be written in the following shorthand notation ... 

It must lose two electrons in its 3s orbital to obey the octet rule. This creates a magnesium ion with a charge of +2. Thus, a magnesium ion has the same electron configuration as the sodium ion but a different charge. Both ions have the same stable electron configuration as the noble gas neon ... 

E—This configuration represents a noble gas (neon). The outer s and p orbitals are filled. 

Neon + water. The only solubility data above 350 K are the data of Potter and Clynne (6). These were combined with Battino s selected data (1) for the linear regression. Figure 3 shows the extrapolation of Battino s equation, which is much too high, and the curves for both the three and four constant fits to the entire data set. Values of the parameters for the four constant equation are given in Table V. The four constant equation gives a better fit to the data at the low temperature than does the three constant equation. Of the five noble gas + water systems, the neon + water system is the only one for which the Potter and Clynne values are lower than Battino s selected values near 350 K temperature where the data sets overlap. 

Neon is basically inert and does not normally form compounds. However, it was recently discovered that, under certain conditions of ionization, it could form the ionized two-atom NeH. Neon is still considered a noble gas that is nonreactive. 

The possible states of electrons are called orbitals. These are indicated by what is known as the principal quantum number and by a letter—s, p, or d. The orbitals are filled one by one as the number of electrons increases. Each orbital can hold a maximum of two electrons, which must have oppositely directed spins. Fig. A shows the distribution of the electrons among the orbitals for each of the elements. For example, the six electrons of carbon (B1) occupy the Is orbital, the 2s orbital, and two 2p orbitals. A filled Is orbital has the same electron configuration as the noble gas helium (He). This region of the electron shell of carbon is therefore abbreviated as He in Fig. A. Below this, the numbers of electrons in each of the other filled orbitals (2s and 2p in the case of carbon) are shown on the right margin. For example, the electron shell of chlorine (B2) consists of that of neon (Ne) and seven additional electrons in 3s and 3p orbitals. In iron (B3), a transition metal of the first series, electrons occupy the 4s orbital even though the 3d orbitals are still partly empty. Many reactions of the transition metals involve empty d orbitals—e.g., redox reactions or the formation of complexes with bases. 

British chemist Sir William Ramsay Noble gas that, unlike most, forms several compounds used like neon to produce tube lighting. 

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