Question

In the periodic table the horizontal rows are called _____.

• A. periods
• B. groups

Answer 1

Introduction:

The elements are arranged in groups and periods on similarity in chemical property and in increasing atomic number is called modern periodic table.The elements in periodic table are placed in periods and groups.

Periods are horizontal rows that has increasing atomic numbers. There are 7 periods.

Final answer:

In the periodic table the horizontal rows are called periods.