Chapter 11.3, Problem 2RQ

Interpretation Introduction

Interpretation :

The given figure is to be drawn as well as the different types of sublevels for each principal energy is to be filled.

Concept Introduction :

According to the Aufbau principle, electrons are filled into the orbitals in the ascending order of energy levels of the orbital and the lowest energy levels of the available orbitals are firstly occupied before the higher energy levels.

Answer to Problem 2RQ

The filling of electrons for each principal energy level is done in the way which is given below,

Explanation of Solution

According to the Aufbau principle, the lowest energy levels of the available orbitals are firstly occupied before the higher energy levels. So, the filling starts from the 1s orbital for first principal energy level $\left(n=1\right)$ then electron enters into the 2s orbital of second principal energy level $\left(n=2\right)$ . After that electron enters the 2p orbital and then 3s orbital and in that case, the electron entered the 2p orbital first because it has lower energy as compared to the 3s orbital. Hence, the energy level of the orbital is determined by the sum of azimuthal and principal quantum number.

Conclusion

The electrons are filled in the order of 1s, 2s,2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p and so on.