Electronic configurations sodium

The third period begins with sodium and ends with argon The atomic number Z of sodium is 11 and so a sodium atom has 11 electrons The maximum number of electrons in the Is 2s and 2p orbitals is ten and so the eleventh electron of sodium occupies a 3s orbital The electron configuration of sodium IS 2s 2p 2p 2p is ... 

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... 

Transfer of an electron from a sodium atom to a chlorine atom yields a sodium cation and a chloride anion both of which have a noble gas electron configuration... 

Only body-centered cubic crystals, lattice constant 428.2 pm at 20°C, are reported for sodium (4). The atomic radius is 185 pm, the ionic radius 97 pm, and electronic configuration is lE2E2 3T (5). Physical properties of sodium are given ia Table 2. Greater detail and other properties are also available... 

The alkali metals form a homogeneous group of extremely reactive elements which illustrate well the similarities and trends to be expected from the periodic classification, as discussed in Chapter 2. Their physical and chemical properties are readily interpreted in terms of their simple electronic configuration, ns, and for this reason they have been extensively studied by the full range of experimental and theoretical techniques. Compounds of sodium and potassium have been known from ancient times and both elements are essential for animal life. They are also major items of trade, commerce and chemical industry. Lithium was first recognized as a separate element at the beginning of the nineteenth eentury but did not assume major industrial importance until about 40 y ago. Rubidium and caesium are of considerable academic interest but so far have few industrial applications. Francium, the elusive element 87, has only fleeting existence in nature due to its very short radioactive half-life, and this delayed its discovery until 1939. 

Write out the electron configuration of sodium, magnesium, and aluminum and find the ionization energies for all their valence electrons (Table 20-IV, p. 374). Account for the trend in the heats of vaporization and boiling points (Table 20-1) of these elements. Compare your discussion with that given in Section 17-1.3. 

In the classroom, ionic bonding is mostly introduced by the example of simple ionic substances like sodium chloride. Starting from the electronic configuration of... 

Atoms go about getting eight valence electrons in the least energetic fashion. Sodium has the following electron configuration ... 

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 ... 

Chlorine would have to lose seven electrons to reach an electron configuration like that of neon. But if it gained one, it would have the same stable electron configuration as argon. So that is what chlorine does. If it meets an atom with a high-energy valence electron, such as sodium, the electron migrates to the chlorine atom and forms a chloride ion ... 

EXAMPLE 17.12. Determine the detailed electron configuration of sodium. 

A more detailed representation of the electron configuration of sodium is Na Is2 2s2 2p6 3s1 (subshell notation) instead of simply Na 2, 8, 1 (shell notation). 

The heat of the flame vaporises the compound, producing some sodium and chlorine atoms (electron configuration of Na 1 s2 2s2 2p6 3s1). 

Figure 11.1 Simple model of valency and bonding. The sodium atom (Z = 11) has electronic configuration ls22s22p63s1, drawn simply as (2, 8, 1) (i.e., showing all the n = 2 electrons as a single orbital). Chlorine (Z = 17) is s22s22p63s23p5, drawn as (2, 8, 7). In bonding to form the ionic compound NaCl, the outer (3s) electron of Na is donated to the outer orbital of Cl, giving both a full outer orbital of eight electrons, and leaving the sodium one electron short (i.e., the Na+ ion) and chlorine one extra (Cl-).

Sodium loses its valence electron and its electron configuration becomes identical to that of neon Is2 2s2 2p6. Likewise, the valence shell of chlorine becomes completely filled and its electron configuration resembles that of argon. As a result, during the reaction... 

The condensed electron configuration for a nitrogen atom, for example, is [He]2s 2p. The notation [He] is used to represent Is. For a sodium atom [Z = 11), the condensed electron configuration is [Ne]3s. Here, [Ne] represents, ls 2s 2p . Be aware that condensed electron configurations are simply convenient short forms. Thus, [Ne]3s does not mean that a sodium atom is the same as a neon atom plus one electron. Sodium and neon are different elements because the nuclei of their atoms are completely different. 

Use the aufbau principle to write complete electron configurations and complete orbital diagrams for atoms of the following elements sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, and argon (atomic numbers 11 through 18). 

Write the electron configuration and draw an orbital diagram to show the first excited state of a sodium atom. Assume that the outermost electron is excited. 

For atomic (gas) sodium (Na), the electronic configuration is ls 2s 2p 3s, leading to filled electronic energy levels Is, 2s and 2p, while the 3s level is half-filled. The other excited levels, 3p, 4s..., are empty. In the solid state (the left-hand side in Figure 4.6), these atomic energy levels are shifted and split into energy bands bands Is, 2s and 2p are fully occupied, while the 3s (/ = 0) band, the conduction band, is half-filled, so that a large number N 21 + l)/2 = N/2) of empty 3s excited levels is still available. As a result, electrons are easily excited into empty levels by an applied electric field, and so become free electrons. This aspect confers the typical metallic character to solid sodium. 

As a relevant example, Figure 6.4 shows the room temperature absorption spectrum of Eu + in sodium chloride (NaCl). In this crystal, europium is incorporated in the divalent state, replacing Na+ lattice ions. The spectrum of Eu + ion in NaCl consists of two broad bands, centered at about 240 nm and 340 nm, which correspond to transitions from the ground state ( 87/2) of the 4f electronic configuration to states of the 4f 5d excited electronic configuration. In fact, the energy separation between... 

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