The principles that gives the correct explanation why ground state electronic configuration of $Si$ is
and not
is:

If carbon atom has electronic configuration 1$s^6$, it would have energy lower than that of the normal ground state configuration 1$s^2$ 2$s^2$ 2$p^2$. Yet 1$s^6$ is not observed because it violates

Nitrogen has the electronic configuration $1s^2,2s^{2}2p_x^{1}2p_y^{1}2p_z^1$ and not $1s^2,2s^{2}2p_x^{2}2p_y^{1}2p_z^0$ which is determined by

Question 10

Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons ?

(a) Pauli's exclusion principle

(b) Heisenberg's uncertainty principle

(c) Hund's rule of maximum multiplicity

(d) Aufbau principle