The
table
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- Columns connected to the various chemical groups
are numbered according to the new (1, 2, ... 32)
and old (1A, 2A, ... 8B) system of IUPAC.
- At the right is seen the numbering 0, 1, 2, 3 of the double-shells.
These numbers indicate at the same time the maximal
angular momentum lmaxoccuring in the respective
double-shell.
- The letters s, p, d, f at the heads of the columns
refer to the angular momenta l = 0, 1, 2, 3
of the boxes in the respective columns.
- As a consequence, the number of the boxes
- in the double-shell #0 is 1 with lmax = 0
- in the double-shell #1 is 2 with lmax = 1
- in the double-shell #2 is 3 with lmax = 2
- in the double-shell #3 is 4 with lmax = 3
The total number of boxes up to the element 120 is 10.
- The lower halves of the double-shells are designated
by the topical quantum number c = -1/2,
the upper halves carry c = +1/2.
This topical quantum number is not shown explicitly in the PSE table.
- The left halves of the boxes are designated
by the spin quantum number s = -1/2,
the right halves carry s = +1/2.
This spin quantum number is not shown explicitly in the PSE table.
Electronic states in the Double-Shell PSE are
fourfold degenerate
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Build up
principle
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The build up (Aufbau) principle for this table is simple:
Starting from the bottom of the table, for each halve of a
double shell, electrons start to occupy states of the highest
angular momentum l = lmax and
then proceed to states of lower angular momentum until
l = 0.
In this presentation, the bottom of the table stands at the same
time for the bottom of the potential well seen by the electrons.
The positive charge of the nucleus provides the overall
confinement of the core electrons and electric neutrality of the atom,
but does not determine details of the elecronic structure. - For
highly ionized atoms, the nuclear charge dominates and the
build up prinziple becomes that of hydrogen.
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