The electronic configuration of an element is related to its position on the periodic table.
The links are:
|Electronic configuration feature||Link to the periodic table|
|Number or numbers of circles||Period number|
|Number of electrons in outermost shell||Group number|
|Total number of electrons in all shells||Atomic number|
The electronic configuration of sodium (2.8.1) shows that sodium, Na:
The electronic configurations of atoms help explain the properties of elements and the structure of the periodic table. When atoms collide and react, it is the outer electrons that meet and interact. So, elements in the same group have similar chemical properties because they have the same number of electrons in their outer shell.
The electronic configurations of the elements in group 1:
The atoms of all group 1 elements have similar chemical properties and reactions because they all have one electron in their outer shell. Similarly, the atoms of all group 7 elements have similar chemical properties and reactions to each other because all of them have seven electrons in their outer shell.