The number of unpaired electrons in cobalt atom is (atomic number of $Co = 27$)

Which electron is associated with the least energy?

Select the correct statements for quantum numbers.
$(i)$ Magnetic quantum number $(m_l)$ gives information about the spatial orientation of orbitals with respect to the standard set of coordinate axes.
$(ii)$ Electron spin quantum number is represented by '$s$' and has values of $\pm \frac{1}{2}$.
$(iii)$ Principal quantum number $(n)$ determines the size of the orbitals and also,to a large extent,the energy of the orbitals.

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?

The number of possible spatial orientations of an electron in an atom is given by its

The electronic configuration of $Sc$ $(Z = 21)$ is: