engineering recuitment BARC Stipendiary Trainee Category II 2023 Mock Test General Science Chemistry Classification of Elements and Periodicity in Properties
Which of the following statements about the Modern Periodic Table is correct:
1
It has 18 horizontal rows known as Periods
2
It has 7 vertical columns known as Periods
3
It has 18 vertical columns known as Groups
4
It has 7 horizontal rows known as Groups