Question

groups and periods are there in the modern periodic table.

• A. 18
• B. 7
• C. 8
• D. 20

Answer 1

Answer: (A), (B)

The correct options are
A 18
B 7

In the modern periodic table, there are 18 columns called groups and 7 rows called periods.
The seventh period is still incomplete in the sense that there are more elements being discovered which will find a place in this row. While their structure can be predicted, most properties cannot be confirmed until tangible proof of existence is witnessed.