The set of principal $(n)$,azimuthal $(l)$ and magnetic $(m_l)$ quantum numbers that is not allowed for the electron in $H$-atom is

If the electronic configuration of a nitrogen atom were $1s^7$,its energy would be lower than that of the ground state configuration $1s^2\,2s^2\,2p^3$ due to being closer to the nucleus. However,the $1s^7$ configuration is not observed because it violates which of the following rules?

When the value of the principal quantum number $n$ is $3$,what are the permitted values of the azimuthal quantum numbers $l$ and the corresponding magnetic quantum numbers $m$?

The order of increasing energies of the orbitals follows:

Which of the following sets of quantum numbers is not possible?

The number of unpaired electrons in the excited state of carbon is equal to the number of unpaired electrons in which of the following?