The order of filling of electrons inthe orbitals of an atom will be

Options

(a) 3d, 4s, 4p, 4d, 5s
(b) 4s, 3d, 4p, 5s, 4d
(c) 5s, 4p, 3d, 4d, 5s
(d) 3d, 4p, 4s, 4d, 5s

Correct Answer:

4s, 3d, 4p, 5s, 4d

Explanation:

The sub-shell with lowest value of (n + l) is filled up first. When two or more sub-shells have same (n + l) value the subshell with lowest value of ‘n’ is filled up first therefore the correct order is orbital 4s3d4p5s4d