In an atom the number of electrons in N - Shell is equal to the number of electrons in K, L and M shells. Answer the question.
Which is the outermost shell ?
Explanation :
`K = 1 s^(2) (2)` electrons
`L = 2s^(2) 2p^(6) (8) ` electrons
M = `3s^(2) 3p^(6) 3d^(10)` (18) electrons
Total (28) electrons
`N = 4s^(2) 4p^(6) 4d^(10) 4f^(10) ` (28) electrons
To fill `4f^(10) , 1s^(2) , 2s^(2) 2p^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(2) 3d^(10) 4p^(6) 5s^(2) 4d^(10) 5p^(6) 6s^(2)` should be filled Hence , the electronic configuration is `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(2) 3^(10) 4p^(6) 5s^(2) 4d^(10) 5p^(6) 6s^(2) 4f^(10)` .

Explanation

The outermost shell is n = 6 . `[6s^(2)]`