How many periods are in the periodic table?

Question

How many periods are in the periodic table?

Answer 1

Seven

Answer 2

there are nine1!!!

dont believe wikkipedia they can have the wrong answer alot of times!!!!!!! trust me!!!!!  

Answer 3

Periods are the horizontal rows in the Periodic Table. There are seven.

Now, some of you have said that there are nine, because in the standard drawing of the Periodic Table there are indeed nine horizontal rows. But, those bottom two (lanthanoids and actinoids) actually belong to the sixth and seventh rows, respectively. The true form of the Periodic Table looks like this:

http://en.wikipedia.org/wiki/Periodic_ta...

Answer 4

there are 9 periods it go's 1 to 8 then 0

Answer 5

There are 7 periods(horizontal rows) and 18 groups(vertical columns)

Answer 6

I'm pretty sure that there's nine