A neutral atom of an element has ` 2 k , 8L, 8L, 9M` and ` 2N` electrons . Find out the following :
(a) Atomic no.
(b ) total no. of s-electrons ,
(c ) total no. of s-electrons ,
(d) total no. of s-electrons ,
(e ) Valency of element .
(f) No, of unpaired elecrons) .

Explanation

Deltaronic configuraion fo neutral atom :
` 9 1s^2 /K , ( 2s^2 2P^6)/(L) , ( 3s^2 3P^6 3d^1)/M , ( 4s^1 )/N`
(a) At. No . = Total no. fo electron in nertral atom ` =- 21`
( b) Total no .of s-electrons `= 8`
( c) Total no. of d-electrons =`21`
(d) Total no. of d-electron `= 1`
( e) Valency fo element ` = + 2` and ` +3`
( due to of electron in outer shell and penultimate d-subshell )
(f) No. of upaired electrons ` = 1 ( "of " 3 d)` .