The angular momentum of a $p$-orbital electron is given by:

Two statements are given below:
Statement $I$: In $H$ atom, the energy of $2s$ and $2p$ orbitals is same.
Statement $II$: In $He$ atom, the energy of $2s$ and $2p$ orbitals is same.
The correct answer is:

The electronic configuration,which obeys Hund's rule for the ground state of carbon atom is

Which set of quantum numbers is not possible from the following?

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 $m$?

Which of the following sets of quantum numbers is correct for an electron in a $4f$ orbital?