If $n = 3$,which of the following values of $l$ is correct?

Following Hund's rule,which element contains six unpaired electrons?

The correct order of energy for orbitals in a multi-electron atom is:

Which of the following outer electronic configurations represents argon?

Not considering the electronic spin,the degeneracy of the second excited state $(n=3)$ of $H$ atom is $9$,while the degeneracy of the second excited state of $H^{-}$ is

The electronic configuration of three elements $A$,$B$,and $C$ are given below. Stable form of $A$ may be represented by the formula:
$A : 1s^2, 2s^2, 2p^6$
$B : 1s^2, 2s^2, 2p^6, 3s^2, 3p^3$
$C : 1s^2, 2s^2, 2p^6, 3s^2, 3p^5$