The orbital angular momentum for a $d$-electron is

Write about the magnetic quantum number $(m_{l})$.

The quantum number which explains the line spectra observed as doublets in the case of hydrogen and alkali metals,and doublets and triplets in the case of alkaline earth metals is:

The number of electrons present in all the completely filled subshells having $n=4$ and $s=+\frac{1}{2}$ is . . . . . . . (Where $n=$ principal quantum number and $s=$ spin quantum number)

The maximum number of orbitals present in $n=4$ energy level of an atom and the maximum number of electrons with spin value $+\frac{1}{2}$ in the same orbitals are,respectively.

Which of the following combinations of quantum numbers is allowed?