The total number of unpaired electrons in $d$-orbitals of atoms of element of atomic number $29$ is

The $39^{th}$ electron of an element enters which of the following subshells?

Find the number of electron pairs in $P$ atom with $l = 1$ and $m = 0$.

Which orbital has two angular nodal planes?

Arrange the following atomic orbitals of multi-electron atoms in order of increasing energy.
$A$. $n=3, l=2, m=+1$
$B$. $n=4, l=0, m=0$
$C$. $n=6, l=1, m=0$
$D$. $n=5, l=1, m=+1$
$E$. $n=2, l=1, m=+1$
Choose the correct answer from the options given below:

The total number of magnetic quantum numbers for a $d$-orbital is given by