The number of unpaired electrons in the ground state of a nickel atom is $(Atomic \ number \ of \ Ni = 28)$.

The correct order of the penetration effect of different orbitals is ..........

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 number of protons in the nucleus of an element that has the maximum number of unpaired electrons in the $2p$ subshell?

The orientation of an atomic orbital is governed by

Which of the following sets of quantum numbers is not allowed?