question 6. the horizontal rows are called. there are in the periodic table.

question 6. the horizontal rows are called. there are in the periodic table.

question 6. the horizontal rows are called. there are in the periodic table.

Answer

Brief Explanations:

In the periodic table, horizontal rows are called periods. There are 7 periods in the periodic table.

Answer:

The horizontal rows are called periods. There are 7 periods in the periodic table.