An electron is in one of the $3d$ orbitals. Give the possible values of $n$,$l$,and $m$ for this electron.

Correct statements for an element with atomic number $9$ are:
$A.$ There can be $5$ electrons for which $m_{s}=+\frac{1}{2}$ and $4$ electrons for which $m_{s}=-\frac{1}{2}$
$B.$ There is only one electron in $p_z$ orbital
$C.$ The last electron goes to an orbital with $n=2$ and $l=1$
$D.$ The sum of angular nodes of all the atomic orbitals is $1$
Choose the correct answer from the options given below:

The number of valence electrons in one mole of nitride ion is ............ mole.

$A$: The energy of an electron can be determined by the principal quantum number.
$R$: The principal quantum number $(n)$ determines the possible distance of the electron from the nucleus.

What is an atomic orbital?

In an atom,how many orbital$(s)$ will have the quantum numbers $n = 3, l = 2$ and $m_l = +2$?