Question

How to find group number and periodic number of elements in modern periodic table... ​

Answer 1

Answer:

Firstly we have to find the electronic configuration of the given element.

then the number of shell = the period number

the number of electrons in valence shell = the group number

but if if the group number is 123 then the group number will be same. but if more than 3 then 10 will be added.

ty....