In Mendelev's modified periodic table, there are_________vertical column called groups.

In Mendeleev's original periodic table, there were six horixontal rows (called seried) further subdivided to give a total of 12 . In Mendeleev's modified periodic table, there are ________horizontal rows (called periods).

In the periodic table, the vertical columns are called ______ (periods/groups)

In the modified Mendeleev's periodic table, the 18 vertical columns were divided into______groups.

The short form of the modern periodic table of the elements (also called Bohr's table) is the most convenient and widely used version of the periodic table. It consists of_______horizontal rows called periods and________vertical columbs called groups.

Vertical columns in the periodic table are called ________

Group 16 of the periodic table is called as ________