Question

What is chemical periodicity? what is it's cause?​

Answer 1

Answer:

The cause of periodicity is the recurrence of similar electronic configuration i.e. same number of electrons in the outermost orbit.In a particular group, electrons in the outermost orbit remain the same i.e. electronic configuration is similar.

Explanation:

Answer 2

Answer:

The periodical repetition of similar properties of the elements after certain regular intervals when the elements are arranged in order of increasing atomic number is called periodicity. This property is due to the recurrence of similar valence shell configuration after regular intervals.