Define the mordern periodic law . Discuss the construction of the long form of the periodic table .

Explanation

Modern Periodic Law : " the physical and chemical properties of elements are the periodic function of the electronic configuration of their atoms " .
Construction of mordern periodic table :
1 ) Based on the modern periodic law , the modern periodic table is proposed .
2 ) This periodic table is known as long form periodic table .
3 ) Long form periodic table is the graphical represention of Aufbau principle .
4 ) The modern periodic table has 18 vertical columns called groups and 7 horizontal rows known as periods .
5 ) there are 18 groups , represented by using ROman unmerals I to VIII , with letters A and B in traditional notation (or ) 1 to 18 by ARabic numerals .
There are 7 periods . these periods are represented by Arabic numerals 1 to 7 .
7 ) The number of main shells present in the atom of particular atom decides to whcih period it belongs .
8 ) first period consits 2 elements , `2^(nd ) ` and `3^(rd ) ` periods contains 8 elements each , `4 ^(th) ` and `5 ^(th ) ` periods contains 18 elements each , `6 ^(th ) ` period contains 32 elements and `7 ^(th)` period is incomplete .
9 ) the elements are Classified into s, p,d and f block elements
10 ) Inert gases are placed in `18 ^(th ) ` group .