the columns on the periodic table are called and there are of them. periods groups 18 8 7

the columns on the periodic table are called and there are of them. periods groups 18 8 7

the columns on the periodic table are called and there are of them. periods groups 18 8 7

Answer

Brief Explanations:

In the periodic table, columns are called groups. There are 18 groups in the standard periodic table.

Answer:

groups, 18