Question

how does the electronic configuration of an atom relate to its position in the modern periodic table

Answer 1

in periodic tables different group numbers have different valency so by the number of valency electron one can find position of elements in periodic table

Answer 2

The correct answer is....

An atom according to its atomic number arranges the electrons in the shells and when all electrons are arranged then the electron (valence electrons) in valence shell loses or gains electrons to complete octet and by doing so it gains negative or positive valency.

Gains electrons......negative charge

Lose electrons........positive charge.

Valency is based on electronic configuration.