Merits of the long form of periodic table:
(i) Fundamental property as basis of classification:
It is based on the atomic number of elements which is the most fundamental property of elements.
Image Source: cdn.publishyourarticles.net
(ii) Similarity between structure and properties of elements in placement:
ADVERTISEMENTS:
The elements are arranged according to their electronic configurations. All the elements with similar electronic configurations are put in the same group. Thus it gives the relationship between atomic structure and properties of elements.
(iii) Periodicity explained:
It explains the reason for the periodicity in properties of elements. The electronic configurations of the elements are repeated at regular intervals; therefore, the properties of the elements are repeated at regular intervals.
Defects of the long form of the periodic table:
(i) The position of hydrogen is still not clear although it is generally grouped with alkali metals.
ADVERTISEMENTS:
(ii) There is no place for lanthanides and actinides in the main body of the table.