Answer:
This question is incomplete
Step-by-step explanation:
This question is incomplete. However, the period of the periodic table are the horizontal (left to right) rows in the periodic table. Elements in the same period have the same number of electron shells. There are seven periods in the periodic table.
The periodic table of elements is the table that contains all chemical elements arranged according to there atomic number. Atomic number is the number of protons present in the nucleus of an atom.