Question

Define Periodicity , Periods and Groups .​

Answer 1

Answer:

periodicity : the properties appearing at regular intervals.

periods : 7 horizontal rows in the periodic table which indicate the number of shells of each element.

groups : 18 vertical columns in the periodic table which signify the number of valence electrons of each element. all elements in the same group have same valency.

Answer 2

Answer:

The systematic arrangements of elements in order to make there studies possible is known as periodic table.