Answer:
Explanation:
To show the sequence of electrons filling sublevels in an atom, the Aufbau's principle is one of the tenets that must be satisfied to write a proper notation.
- Aufbau's principle states that "the sublevels with lower energies are filled up before those with higher energies".
- Note that based on this principle, we are not inferring that sublevels are filled in numerical order.
- The patter of filling is shown below:
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f e.t.c