Question

Is there any deleted topic in Periodic Classification?​

Answer 1

$\bold{ANSWER≈}$

nothing is deleted from that chapter. you have to read full chapter.

Answer 2

Periodic Classification of Elements Characteristics

Atomic number of an element is equal to the number of protons inside the nucleus of its atom. The general features of the long form periodic table are: There are in all, 18 vertical columns and 18 groups in the long form periodic table.