If the nitrogen atom had electronic configuration $1s^7$,it would have energy lower than that of normal ground state configuration $1s^22s^22p^3$,because the electrons would be closer to the nucleus.Yet $1s^7$ is not observed because it violates

Question

$\begin{array}{1 1}(a)\;\text{Heisenberg's uncertainty principle}\\(b)\;\text{Hund's rule}\\(c)\;\text{Pauli exclusion principle}\\(d)\;\text{Bohr postulate of stationary orbits}\end{array}$