Tuesday, October 15, 2013

As we see, if the sodium loses an electron, will remain as sodium dta 5 cation, Na +, and acquire n

Fundamentals of ionic and types of crystal lattices dta 5 | Quimitube
Ionic bonding occurs between metal components (electropositive) and nonmetals (electronegative). For example, combinations of alkali and alkaline earth metals (the first two groups of the periodic table) and halogens (F, Cl, Br ...) are typically ionic compounds. As its name suggests, an ionic compound has a link that is given by electrostatic attraction between ions: between cations from metal, positively charged, and from non-metal anions, negatively charged.
How is it possible that these compounds form ions? Well, we could say generically that metals have a tendency to give up electrons and non-metals have a tendency to capture them. Although, as explained dta 5 in the video the process is endothermic (you must provide energy to form ions), the energy increase dta 5 will be offset by the subsequent formation of a crystal lattice.
Consider the sodium chloride, NaCl, common salt (table salt). Sodium is an alkali metal is, therefore, an electron in the valence shell. Chlorine is a halogen which has 7 electrons in the valence shell. Thus, their electronic configurations are:
As we see, if the sodium loses an electron, will remain as sodium dta 5 cation, Na +, and acquire noble gas electron configuration above, the neon. For its part, bleach, very electronegative, has 7 electrons in the last layer. It makes no sense to lose 7 electrons, but it captures one (the sodium electron yield) to give the chloride anion and be, too, with a noble gas electron configuration, in this case the argon. Recall that the electronic configuration of a noble gas with 8 electrons in the last layer, is very stable, so that the Na + and Cl-are also very stable. We will therefore:
Therefore, in the formation of a metal ion composed donates electrons, dta 5 leaving as a cation, and no electron withdrawing metal, leaving as an anion. The cations and anions formed are maintained after together by electrostatic attraction, forming a highly ordered crystal lattice.
Although we have said that metals tend to give up electrons and nonmetals to capture them, you can see in the previous data for one mole of Na + and one mole of Cl-is necessary to provide an overall energy of 146 kJ / mol (495-349). This initial energy contribution is compensated by the subsequent formation of a compound in a network, which is the ionic compound. In forming the ionic compound shows a very large amount of energy, dta 5 which is called lattice energy.
What does it mean to be a crystal lattice? Means a solid structure which is highly ordered, comprising cations and anions always dta 5 in the same ratio (the stoichiometric ratio for maintaining electrical neutrality) and in the same fixed positions. Fixed positions established for the cations and anions network type dependent ionic it. Not all networks are the same ion, have various types of structures.
As each ion generates around an electric field that is equal in all three directions of space, each tends to surround himself with a fixed number of counterions. This number is called the coordination number and coordination number. The coordination number varies with the type of network. For example, in the case of NaCl, sodium surrounds each 6 chlorides and each is surrounded by six chloride sodes. The coordination number for both ions is 6, a structure (6,6), which structure is called face-centered cúbida:
Crystal structure of sodium chloride, NaCl. The chlorides are green and in purple sodes. It can be seen that each is surrounded by six sodium chloride (coordination number) because there is no room for more.
The coordination number of the cation and anion in a crystal lattice depends essentially on two factors: size of the ions. The radius of the ions will set the distance that can be placed by a simple matter of space. For example, the sodium cation, Na +, has a radius of 0.95 A, and 1.81 A. chloride This difference in size makes each sodium can surround only 6 chlorides. dta 5 In the case of ionic networks whose sizes are more similar, dta 5 such as cesium chloride, CsCI (Cs + Cl-1.70 A and 1.81 A), the ions may be surrounded by a greater number of ions of opposite charge, and This network presents ionic coordination (8,8), which is called the body-centered cubic. Each ion is surrounded by eight cesium chloride, and every 8 cesios chloride.
Charge of the ions. As the crystal dta 5 is electrically neutral, if the ions have different load this condition the estequi

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