S Subshell

For any given value of n, there can be a value of / = 0, corresponding to an s subshcll. For / = 0 there can be only one possible m value m = 0. Hence, n. /, and m arc all specified for a given s subshell. Electrons can then have spin values of s = + ors= - i. Thus, every possible set of four quantum numbers is used, and there arc no other possibilities in that subshcll. Each of the two electrons has the first three quantum numbers in common and has a different value of s. The two electrons arc said to be paired. 

An effective way to determine the detailed electron configuration of any element is to use the periodic table to determine which subshell to fill next. Each s subshell holds a maximum of 2 electrons each p subshell holds a maximum of 6 electrons each d subshell holds a maximum of 10 electrons and each / subshell holds a maximum of 14 electrons (Table 17-5). These numbers match the numbers of elements in a given period in the various blocks. To get the electron configuration, start at hydrogen (atomic number = 1) and continue in order of atomic number, using the periodic table of Fig. 17-10. 

Ans. (a) 10. This is a d subshell, with five orbitals corresponding to rn values of - 2, - 1, 0, 1, 2. Each orbital can hold a maximum of 2 electrons, and so the subshcll can hold 5x2= 10 electrons, ib) 2. This is an s subshell, (c) 6. This is a p subshcll (with three orbitals), (d) 2. This is an s subshcll. The principal quantum number docs not matter. [Compare part (/>).]... 

The energy gap (AE) between the 3p and 3 s subshells corresponds to the frequency of yellow light in the visible region of the spectrum. 

The order of subshell filling is s2s2p3s3p4s3d4p5s4d5p6s4f 5d6pls5f 6d. An s subshell can have a maximum of 2 electrons, a p subshell can have 6 electrons maximum, a d subshell can have 10, and an / subshell can have 14. 

There are several ways of indicating the arrangement of the electrons in an atom. The most common way is the electron configuration. The electron configuration requires the use of the n and / quantum numbers along with the number of electrons. The principle quantum number, n, is represented by an integer (1,2,3. ..), and a letter represents the l quantum number (0 = s, 1 = p, 2 = d, and 3 = f). Any s-subshell can hold a maximum of two electrons, any p-subshell can hold up to six electrons, any d-subshell can hold a maximum of 10 electrons, and any f-subshell can hold up to 14 electrons. 

Maximum number of electrons for s-subshells = 2, p-subshells = 6, d-subshells = 10, f-subshells = 14. 

The even higher value of Be (greater than B) is due to the increased stability of the electron configuration of Be. Beryllium has a filled s-subshell. Filled subshells have an increased stability, and additional energy is required to pull an electron away. Give yourself 1 point for the filled subshell discussion. 

With the exception of hydrogen, the subshells within each shell have slightly different energies the s subshell has the lowest energy, then p, then d, and so on. The table shows the different subshells present in each shell. Each type of subshell contains one or more orbitals. 

There will be two electrons in the s subshell, six electrons in the p subshell and 10 electrons in the d subshell, which means that there must be 14 electrons in the f subshell. Therefore there must be seven f orbitals to accommodate these 14 electrons. 

Orbitals can be grouped into successive layers, or shells, according to their principal quantum number n. Within a shell, orbitals are grouped into s, p, d, and f subshells according to their angular-momentum quantum numbers l. An orbital in an s subshell is spherical, an orbital in a p subshell is dumbbell-shaped, and four of the five orbitals in a d subshell are cloverleaf-shaped. 

In looking for other trends in the data of Figure 6.6, the near-zero Eea s of the alkaline earth metals (Be, Mg, Ca, Sr, Ba) are particularly striking. Atoms of these elements have filled s subshells, which means that the additional electron must go into a p subshell. The higher energy of the p subshell, together with a relatively low Zeff for elements on the left side of the periodic table, means that alkaline earth atoms accept an electron reluctantly and have Eea values near zero. 

The electrons in an uncharged arsenic atom (As0) are located in the s subshell of the first principal quantum number (n = 1), the s and p subshells of principal quantum numbers 2-4 (n = 2-4), and the d subshell of the third principal quantum number (n = 3). Specifically, the As0 electron configuration may be written as ... 

The s subshells have one orbital, the p subshells have three, and the d subshell has five. Each orbital may contain up to two electrons. For example, the 2p subshell has a total of six electrons, where each of the three 2p orbitals contains two electrons (Faure, 1998), 63-71. 

That means, since for 1=0 the only allowed value for m, in the s subshell is 0, there is one orbital corresponding to this value of m, which is the 2s orbital. 

The s subshell contains one orbital or region where an electron can be found. The p sublevel has three orbitals, while the d and f levels have five and seven orbitals, respectively. The shapes of the s and p orbitals are shown in Figure 3.5. 

The alkali and alkaline earth metals have their valence electrons in the s subshells. Groups 13 through 18 have their valence electrons located in the p subshells. The transition elements have their valence electrons in the d subshells, and finally, the lanthanides and actinides have their valence electrons in the f sublevel. 

Now that you understand electron configurations, an orbital diagram can be drawn. Orbital diagrams represent the orbital where each electron is located. An arrow is used to represent each electron spinning in a particular direction. Recall that s subshells have one orbital, p subshells have three orbitals, and d subshells... 

The elements display a periodicity of electronic conf uration. For example, if we examine the detailed electronic configurations of the alkali metals, we find that the outermost shell (specifically, the s subshell) of electrons contains only a single electron in each case. The alkahne earth metals have two outermost electrons. The elements within each other group of the periodic table also have similarities in their outermost electronic configurations. We deduce that the outermost part of the electronic configuration is the main factor that determines the chemical properties of the elements because the periodic table was constructed from data about the properties of the elements. 

Ans. (a) Since the s subshell contains only one orbital, the 2s orbital is the 2s subshell, (b) The 2p subsheU contains three 2p orbitals— known as2px,2py, and 2p. ... 

Each subshell contains orbitals, which are like the rooms of the house at the particular address of the electrons. Each orbital holds a maximum of two electrons. There is only one orbital in each s subshell, three orbitals in each p subshell, five orbitals in each d subshell, and seven orbitals in each/subsheU. Therefore, the s subshell can hold two electrons, the p subshell can hold six electrons, the d subshell can hold 10 electrons, and the/subshell can hold 14 electrons. 

The electron that was added to the helium atom to form the anion could not fit into the s subshell of the first principal quantum shell, because it already had two electrons and so was full. Instead, this extra electron occupied the next available orbital, which was the s subshell of the second principal quantum level. This requires a lot of energy, and so it is difficult. Hence, the He- anion, which it should also be noted is a radical species, is not normally found. 

The second row elements, lithium to neon, sequentially fill the available four subshells in the second principal quantum level, starting with the s subshell and then progressing to the three p subshells. The latter three each have the same... 

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