Considering the definition of period, group and electronic configuration:
The elements are arranged in horizontal rows, called periods, and in columns, called groups.
The Electronic Configuration of the elements is the arrangement of all electrons of an element in energy levels and sub-levels (orbitals).
There are 7 energy levels, numbered from 1 to 7, and in which electrons are distributed, logically in order according to their energy level.
Each level is divided into sub-levels. These sub-levels into which each level is divided can be up to 4. These 4 sub-levels are called: s, p, d, f.
The placement of the elements in the periodic table is done taking into account the electronic configuration.
In each period, the elements whose last level of their electronic configuration coincides with the number of the period appear.
On the other hand, in each group appear the elements that present the same number of electrons in the last occupied level or valence shell.
In summary:
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