7 periods.
There are 7 periods in the modern periodic table.
7
there are 7 periods in the periodic table118
The periodic table has 7 periods on it.
there are 7 periods in the periodic table118
The modern periodic table has seven periods.
7The periodic table has 7 periods and 18 groups.
7The Periodic Table has 7 periods and 18 groups.
Horizontal rows are termed as periods. There are 7 periods in periodic table.
6 periods
Periods are the horizontal rows in the periodic table of Mendeleev; this table contain 7 periods.
There are 7 periods in the modern periodic table.