Question

what is meant by periodicity

Answer 1

Periodicity Definition. In the context of chemistry and the periodic table, periodicity refers to trends or recurring variations in element properties with increasing atomic number. Periodicity is caused by regular and predictable variations in element atomic structure

Answer 2

the periodic property which appears at regular interval is called periodic property and the phenomenon is called periodicity in periodic property .
E.g. atomic radius ,ionosation potential ,etc.