What is the total number of unpaired electrons in an element placed at period-$4$ and group-$12$ either in excited or at ground state?

Consider the following statements:
$(A)$ The principal quantum number $'n'$ is a positive integer with values of $'n'=1, 2, 3, \dots$.
$(B)$ The azimuthal quantum number $'l'$ for a given $'n'$ (principal quantum number) can have values as $'l'=0, 1, 2, \dots, (n-1)$.
$(C)$ Magnetic orbital quantum number $'m_l'$ for a particular $'l'$ (azimuthal quantum number) has $(2l+1)$ values.
$(D)$ $\pm 1/2$ are the two possible orientations of electron spin.
$(E)$ For $l=5$,there will be a total of $11$ orbitals.
Which of the above statements are correct?

What is the meaning of degenerate orbitals?

$(i)$ An atomic orbital has $n=3$. What are the possible values of $l$ and $m_l$?
$(ii)$ List the quantum numbers ($m_l$ and $l$) of electrons for $3d$ orbital.
$(iii)$ Which of the following orbitals are possible? $1p$,$2s$,$2p$,and $3f$.

How many maximum electrons can be accommodated in a $p$-orbital with $n = 6$ and $m = 0$?

In the ground state, an element has $13$ electrons in the $M$ shell. The element is