State modern periodic law. What is the number of groups and periods in the modern periodic table?

Explanation:

According to Modern Periodic Law properties of elements are a periodic function of their atomic number.

It means elements have the same physical and chemical property after a regular interval when arranged according to their atomic number.

In the Modern Periodic Table there are 18 groups and 7 periods.

There are 18 vertical columns called groups.

There are 7 horizontal rows called periods.

Final Answer: According to Modern Periodic Law properties of elements are a periodic function of their atomic number.