How does the electronic configuration of an element give information about the period and the group it belongs to

Electronic configuration of an element gives the information of valence electrons and number of shell present in the element.

Explanation:

Electronic configuration of an element gives the information of valence electrons and number of shell present in the element. We get the information of group number after knowing valence electrons.  

The number of shells present in an element is equal to the period number. Thus, by knowing electronic configuration we know the group number and period number of an element, and the position of an element in the periodic table.