In 1869, Dmitri Mendeleyev published the discovery he made of the periodic table. His information was drawn only from chemistry and the knowledge of atomic weights. Atomic numbers were not known, atomic structure was unknown, the electron was not discovered for nearly 30 years later, not to speak of their arrangement. When atomic structure and electronic configuration was discovered, they explained and refined the Periodic Table.
Electronic configuration, beginning with the electron itself, is what determines the periodicity of the Periodic Table of the Elements.
The Electron.
The electron is the particle which carries the unit of negative electric charge. There is one for every proton in an electrically balanced atom.
The Orbitals
Each orbital holds two electrons.
The Subshells.
The subshells are comprised of orbitals. There are four subshells, designated as: s (sharp), p (principle), d (diffuse), and f (fine). Beginning with the s subshell which has one orbital, two orbitals are added to each successive subshell, so that they have 1, 3, 5, and 7 orbitals.
The s subshell has a single orbital and two electrons.
The p subshell has three orbitals and six electrons.
The d subshell has five orbitals and ten electrons.
The f subshell has seven orbitals and fourteen electrons.
The Shells.
There are seven shells, or energy levels, each of which is comprised of one to four subshells. Beginning with the letter k at the innermost shell and outward, the shells are designated alphabetically as: k, l, m, n, o, p, and q. The subshells are added incrementally to the shells up to the fourth shell, then after the fifth shell the subshells are subtracted incrementally thus:
Shell.................. Subshells .................Electrons
k: ..............................s, ................................2
l: ...............................s, p, ............................8
m: .............................s, p, d, .......................18
n: ..............................s, p, d, f, ....................32
o:.............................. s, p, d, f, ....................32
p: ..............................s, p, d, .......................18
q:.............................. s, p, ............................8
The Periods.
The seven periods correspond to the seven energy levels. But because the outer shell is complete with eight electrons which fill the s and p subshells, the s subshell in the next energy level is begun, and so the beginning of a new period. The d and the f subshells are not filled in the period corresponding to their energy levels, but are filled in the successive one and two periods, respectively. The elements corresponding to filling the d and f subshells are given to the period in which they are filled, thus:
Period................Subshells ..............Number of
...............................Filled...................Elements
1............................... s ................................2
2 ...............................s, p ............................8
3............................... s, p ↓..........................8
4 ...............................s, p, d ↓ ....................18
5 ...............................s, p, d ↓ ....................18
6 ...............................s, p, d, f,................... 32
7 ...............................s, p, d, f, ...................32
Electronic Configuration. This Periodic Table arranges the elements according to their blocks, which places Helium next to Hydrogen, though its chemical group is the Noble Gases. By noting the electronic configuration which is the column of numbers on the upper right of each element it can be seen where each successive electron is added to the shells. The block generally denotes what subshell the electrons are added to. All the anomalous additions fall within the d and f blocks, each of which stand, as it were, a parenthesis between the s and p blocks.
Atomic Numbers. The atomic number of an element is the number of protons in its nucleus. The proton has the unit of positive electric charge which is exactly the compliment of the electron’s negative charge. The same number of electrons balance the positive charge of the nucleus. The structure of the shells and subshells and the order in which electrons are added in successive atomic number to these determines the periodic structure of the table.
Progression of the Shells and Subshells.
The k shell has altogether only a single s subshell, and so the first period has two elements, Hydrogen and Helium, atomic numbers 1 and 2 and have one and two protons respectively. All shells have an s subshell. The first energy level is unique in that it is the only shell that has a single subshell, the remaining six are paired: the second and seventh, l and q shells each have s and p subshells, the third and sixth, m and p shells each have s, p, and d subshells, and the fourth and fifth, n and o shells each have s, p, d, and f subshells. Also the k shell is the only shell that is complete with two electrons. All other outer shells are complete with eight electrons. When the outer shell is complete, that element has practically no chemical attraction to other elements since it does not give up or take on electrons, and is therefore chemically inert. Again, there are two each of the other shells: two s, p; two s, p, d; and two s, p, d, f, but only one s. The elements of the first period share the uniqueness of the first period. Hydrogen is the only element that can exist with no neutrons, it has a chemical bond peculiar to, and named for itself, and has a balance of electropositive and electronegative characteristics. Helium is the only s block element belonging to the p block group, or, if you prefer, it is the only p block element which has no p subshell electrons. Additionally, the greatest nuclear power source is primarily from the fusion of Hydrogen nuclei into Helium nuclei. Other fusion processes yield only a small fraction of the energy produced by this process. Again, the greatest percentage of the mass of the universe is Hydrogen.
The l shell introduces the p subshell and has a total capacity for eight electrons. Correspondingly, the second period has eight elements. With the exception of the k shell, all the shells have a p subshell. When both the s and p subshells are filled in a given shell, the next higher atomic number element begins a new period. Atomic numbers 3 and 4 fill the s subshell and establish the s block the first two left hand columns, Groups IA and IIA (I have given consideration only to the s, p, d, and f blocks in figure #). All of the elements in Group IA have one electron in their outer shell and all the elements in Group IIA have two electrons in their outer shell. The p subshell is filled by atomic numbers 5 - 10 which fully form the top row of the p-block which are Groups IIIA - IIIVA. All of the elements, excepting Helium, in these groups have as many electrons as the number of their group.
The m shell introduces the d subshell. Although this gives this energy level the capacity for eighteen electrons, the third period has only eight elements since only the s and p subshells are filled in the third period, following the pattern of the second period, atomic numbers 11 and 12 in the s block and numbers 13 - 18 in the p block.
The n shell introduces the f subshell. The s subshell of the fourth period is filled corresponding to the first two elements, 19 and 20, in the s block of the fourth period. The next ten electrons are added, more or less regularly, to the d subshell of the m shell, giving the first row of transition elements that lie between the s and p blocks to the fourth period, having atomic numbers 21 - 30. Only when the d subshell of the m shell is full, does the p subshell begin to fill. Elements 31 - 36 correspond to the p subshell of the fourth period. The fourth period has eighteen elements.
The o shell repeats the structure of the n shell with the s, p, d, and f subshells and the fifth period repeats the pattern of the fourth period as well. Its s subshell, atomic numbers 37 and 38, is filled, then the d subshell, of the n shell, atomic numbers 39 - 48, is filled before its p subshell, atomic numbers 49 - 54, is filled. The fifth period, repeating the pattern of the fourth, has eighteen elements as the d subshell of the o shell is filled in the sixth period and the f subshell is filled in the seventh period.
The p shell introduces a regressive trend of subshells by subtracting the f subshell from its number and has only the s, p and d subshells, repeating the pattern of the m shell. But at the same time the sixth period progressively adds to its number the elements corresponding to the f subshell of n shell as well as picking up the elements of the d subshell of o shell. The s subshell, atomic numbers 55 and 56, is first filled, then the f subshell in the n shell, atomic numbers 57 - 70*, then the d subshell in the o shell, atomic numbers 71 - 80*, and finally the p subshell, atomic numbers 81 - 86. The sixth period has thirty-two elements.
The q shell continues the regressive pattern introduced in the p shell, subtracting the d subshell, having the structure of the l shell. The seventh period repeats the pattern of the sixth with thirty-two elements. Indeed, they have not all been discovered, or rather, created, but all have been named. The s subshell, atomic numbers 87 - 88, is first filled, then the f subshell of the o shell, atomic numbers 89 -102*, then, presumably, the d subshell of the p shell, atomic numbers 103 - 112*, and finally, again, presumably, the p subshell.
The chiastic structure of the subshells seems to indicate an eighth shell. Such would be like the k shell in two ways: The q shell supplies the final p subshell, and the seventh period fills this p subshell, fills the final d subshell of the p shell, and fills the final f subshell of the o shell. So the pattern of the p, d, and f subshells are completed in the seventh period. If following this pattern, then, an eighth shell would have no more than a single s subshell, and an eighth period would have no more than two elements.
Electronic configuration, beginning with the electron itself, is what determines the periodicity of the Periodic Table of the Elements.
The Electron.
The electron is the particle which carries the unit of negative electric charge. There is one for every proton in an electrically balanced atom.
The Orbitals
Each orbital holds two electrons.
The Subshells.
The subshells are comprised of orbitals. There are four subshells, designated as: s (sharp), p (principle), d (diffuse), and f (fine). Beginning with the s subshell which has one orbital, two orbitals are added to each successive subshell, so that they have 1, 3, 5, and 7 orbitals.
The s subshell has a single orbital and two electrons.
The p subshell has three orbitals and six electrons.
The d subshell has five orbitals and ten electrons.
The f subshell has seven orbitals and fourteen electrons.
The Shells.
There are seven shells, or energy levels, each of which is comprised of one to four subshells. Beginning with the letter k at the innermost shell and outward, the shells are designated alphabetically as: k, l, m, n, o, p, and q. The subshells are added incrementally to the shells up to the fourth shell, then after the fifth shell the subshells are subtracted incrementally thus:
Shell.................. Subshells .................Electrons
k: ..............................s, ................................2
l: ...............................s, p, ............................8
m: .............................s, p, d, .......................18
n: ..............................s, p, d, f, ....................32
o:.............................. s, p, d, f, ....................32
p: ..............................s, p, d, .......................18
q:.............................. s, p, ............................8
The Periods.
The seven periods correspond to the seven energy levels. But because the outer shell is complete with eight electrons which fill the s and p subshells, the s subshell in the next energy level is begun, and so the beginning of a new period. The d and the f subshells are not filled in the period corresponding to their energy levels, but are filled in the successive one and two periods, respectively. The elements corresponding to filling the d and f subshells are given to the period in which they are filled, thus:
Period................Subshells ..............Number of
...............................Filled...................Elements
1............................... s ................................2
2 ...............................s, p ............................8
3............................... s, p ↓..........................8
4 ...............................s, p, d ↓ ....................18
5 ...............................s, p, d ↓ ....................18
6 ...............................s, p, d, f,................... 32
7 ...............................s, p, d, f, ...................32
Electronic Configuration. This Periodic Table arranges the elements according to their blocks, which places Helium next to Hydrogen, though its chemical group is the Noble Gases. By noting the electronic configuration which is the column of numbers on the upper right of each element it can be seen where each successive electron is added to the shells. The block generally denotes what subshell the electrons are added to. All the anomalous additions fall within the d and f blocks, each of which stand, as it were, a parenthesis between the s and p blocks.
Atomic Numbers. The atomic number of an element is the number of protons in its nucleus. The proton has the unit of positive electric charge which is exactly the compliment of the electron’s negative charge. The same number of electrons balance the positive charge of the nucleus. The structure of the shells and subshells and the order in which electrons are added in successive atomic number to these determines the periodic structure of the table.
Progression of the Shells and Subshells.
The k shell has altogether only a single s subshell, and so the first period has two elements, Hydrogen and Helium, atomic numbers 1 and 2 and have one and two protons respectively. All shells have an s subshell. The first energy level is unique in that it is the only shell that has a single subshell, the remaining six are paired: the second and seventh, l and q shells each have s and p subshells, the third and sixth, m and p shells each have s, p, and d subshells, and the fourth and fifth, n and o shells each have s, p, d, and f subshells. Also the k shell is the only shell that is complete with two electrons. All other outer shells are complete with eight electrons. When the outer shell is complete, that element has practically no chemical attraction to other elements since it does not give up or take on electrons, and is therefore chemically inert. Again, there are two each of the other shells: two s, p; two s, p, d; and two s, p, d, f, but only one s. The elements of the first period share the uniqueness of the first period. Hydrogen is the only element that can exist with no neutrons, it has a chemical bond peculiar to, and named for itself, and has a balance of electropositive and electronegative characteristics. Helium is the only s block element belonging to the p block group, or, if you prefer, it is the only p block element which has no p subshell electrons. Additionally, the greatest nuclear power source is primarily from the fusion of Hydrogen nuclei into Helium nuclei. Other fusion processes yield only a small fraction of the energy produced by this process. Again, the greatest percentage of the mass of the universe is Hydrogen.
The l shell introduces the p subshell and has a total capacity for eight electrons. Correspondingly, the second period has eight elements. With the exception of the k shell, all the shells have a p subshell. When both the s and p subshells are filled in a given shell, the next higher atomic number element begins a new period. Atomic numbers 3 and 4 fill the s subshell and establish the s block the first two left hand columns, Groups IA and IIA (I have given consideration only to the s, p, d, and f blocks in figure #). All of the elements in Group IA have one electron in their outer shell and all the elements in Group IIA have two electrons in their outer shell. The p subshell is filled by atomic numbers 5 - 10 which fully form the top row of the p-block which are Groups IIIA - IIIVA. All of the elements, excepting Helium, in these groups have as many electrons as the number of their group.
The m shell introduces the d subshell. Although this gives this energy level the capacity for eighteen electrons, the third period has only eight elements since only the s and p subshells are filled in the third period, following the pattern of the second period, atomic numbers 11 and 12 in the s block and numbers 13 - 18 in the p block.
The n shell introduces the f subshell. The s subshell of the fourth period is filled corresponding to the first two elements, 19 and 20, in the s block of the fourth period. The next ten electrons are added, more or less regularly, to the d subshell of the m shell, giving the first row of transition elements that lie between the s and p blocks to the fourth period, having atomic numbers 21 - 30. Only when the d subshell of the m shell is full, does the p subshell begin to fill. Elements 31 - 36 correspond to the p subshell of the fourth period. The fourth period has eighteen elements.
The o shell repeats the structure of the n shell with the s, p, d, and f subshells and the fifth period repeats the pattern of the fourth period as well. Its s subshell, atomic numbers 37 and 38, is filled, then the d subshell, of the n shell, atomic numbers 39 - 48, is filled before its p subshell, atomic numbers 49 - 54, is filled. The fifth period, repeating the pattern of the fourth, has eighteen elements as the d subshell of the o shell is filled in the sixth period and the f subshell is filled in the seventh period.
The p shell introduces a regressive trend of subshells by subtracting the f subshell from its number and has only the s, p and d subshells, repeating the pattern of the m shell. But at the same time the sixth period progressively adds to its number the elements corresponding to the f subshell of n shell as well as picking up the elements of the d subshell of o shell. The s subshell, atomic numbers 55 and 56, is first filled, then the f subshell in the n shell, atomic numbers 57 - 70*, then the d subshell in the o shell, atomic numbers 71 - 80*, and finally the p subshell, atomic numbers 81 - 86. The sixth period has thirty-two elements.
The q shell continues the regressive pattern introduced in the p shell, subtracting the d subshell, having the structure of the l shell. The seventh period repeats the pattern of the sixth with thirty-two elements. Indeed, they have not all been discovered, or rather, created, but all have been named. The s subshell, atomic numbers 87 - 88, is first filled, then the f subshell of the o shell, atomic numbers 89 -102*, then, presumably, the d subshell of the p shell, atomic numbers 103 - 112*, and finally, again, presumably, the p subshell.
The chiastic structure of the subshells seems to indicate an eighth shell. Such would be like the k shell in two ways: The q shell supplies the final p subshell, and the seventh period fills this p subshell, fills the final d subshell of the p shell, and fills the final f subshell of the o shell. So the pattern of the p, d, and f subshells are completed in the seventh period. If following this pattern, then, an eighth shell would have no more than a single s subshell, and an eighth period would have no more than two elements.
posted by MDB | 11:15 PM
0 Comments:
Post a Comment
<< Home