Why do elements in the same group have similar physical properties?

1 Answer
Jan 1, 2018

All elements in a group have the same number of outermost electrons (valence electrons)

Explanation:

An elements group number also denotes the number of electrons present in it's outermost shells.

These electrons are responsible for the vast majority of chemical properites and reactivities due to respective energy levels of electrons and thus can be used to describe an atoms bonding tendencies.