Question

state the rules followed writing the number of electrons in different energy shells also give atomic structure of any two elements
9th class cbse ​

Answer 1

Explanation:

The following rules are followed for writing the number of electrons in different energy levels or shells.

(i) the maximum number of electrons presents in a shell is given by the formula 2  

where 2 is the orbit number of energy level index 1,2,3... hence the maximum number of electrons in different shells are as follows :  

First orbit or K-shell will be =2×$1^{2}$

=2

Second orbit or L shell will be =2×$2^{2}$

=8

third orbit or M shell will be =2×$3^{2}$

=18

fourth orbits or N-Shell will be =2×$4^{2}$

=32 and so on.

(ii) The maximum number of electrons that can be accommodated in the outermost orbit is 8

(iii) Electrons are not accommodated in a given shell unless the inner shells are filled. That is the shells are filled in a stepwise manner.

Atomic structure of 2 elements :