In an atom first four shells (K, L, M, and N) are completely filled. Then what is the total number of electrons in that atom?
(i) If in an atom the first four shells are completely filled then the total number of the electrons in the atom would be 26.
(ii) This is because the first four shells of the atom are K, L, M and N. using the formula 2(n2) we can find out the maximum electron in each shell which comes out to be
K = 2 electrons
L = 8 electrons
M and N = 18 electrons as
(iii) The maximum number of the electrons in outermost orbit cannot be more than 8.
(iv) So the total number of electrons for first four completely filled shells is 26.