A. 17
B. 18
C. 19
D. None of these.
Submitted by: Nadar Ali Buriro
The modern periodic table was created by Mosley.
There are 7 horizontal rows which are called periods. They are also called series.
Also, the modern periodic table consists of 18 vertical columns which are called groups.
Correct Answer: 18 ✔
Last Updated: November 27, 2022