The maximum number of electrons that can be accommodated in $f$ subshell is

Match the column:

Column-$I$	Column-$II$
$A$. The orbital which has two angular nodes	$P$. $4d_{x^2-y^2}$
$B$. The $d$ orbital with zero nodal plane	$Q$. $3d_{z^2}$
$C$. The orbital with two radial nodes	$R$. $4f$
$D$. The orbital with three angular nodes	$S$. $3s$

Correct match will be $:-$

The electrons would go to lower energy levels first and then to higher energy levels according to which of the following?

In a multi-electron atom,which of the following orbitals have the same energy in the absence of magnetic and electric fields? $(a) n = 1, l = 0, m = 0, (b) n = 3, l = 0, m = 0, (c) n = 2, l = 1, m = 1, (d) n = 3, l = 2, m = 1, (e) n = 3, l = 2, m = 0$

$A$: No two electrons in an atom can have the same set of all four quantum numbers.
$R$: Two electrons in an atom can exist in the same shell,subshell,or orbital only if they have opposite spins.

$(a)$ How many sub-shells are associated with $n=4?$
$(b)$ How many electrons will be present in the sub-shells having $m_{s}$ value of $-1/2$ for $n=4?$