How Many Elements Can Be There In 3rd Period?

How Many Elements Can Be There In 3rd Period? The third period contains eight elements: sodium, magnesium, aluminium, silicon, phosphorus, sulfur, chlorine, and argon. The first two, sodium and magnesium, are members of the s-block of the periodic table, while the others are members of the p-block. How many elements are there in the 3rd