The vertical columns of the Mendeleev’s periodic table is called
 

Concept:

1. In the periodic table, the elements are arranged in vertical columns called groups and horizontal rows known as periods.
2. There are nine groups indicated by Roman Numerals as I, II, III, IV, V, VI, VII, VIII, and zero, and the elements belonging to the first seven groups have been divided into sub-groups designated as A and B on the basis of similarities in properties.