For a sodium atom,the number of electrons with $m = 0$ will be:

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

The correct set of four quantum numbers for the valence electron of rubidium atom $(Z = 37)$ is

How many values of magnetic quantum number are possible for each value of azimuthal quantum number?

The number of radial nodes of $3s$ and $2p$ orbitals are respectively.

The arrangement of orbitals on the basis of energy is based upon their $(n + l)$ value. Lower the value of $(n + l)$,lower is the energy. For orbitals having same values of $(n + l)$,the orbital with lower value of $n$ will have lower energy.
$(I)$ Based upon the above information,arrange the following orbitals in the increasing order of energy.
$(a)$ $1s, 2s, 3s, 2p$
$(b)$ $4s, 3s, 3p, 4d$
$(c)$ $5p, 4d, 5d, 4f, 6s$
$(d)$ $5f, 6d, 7s, 7p$
$(II)$ Based upon the above information,solve the questions given below:
$(a)$ Which of the following orbitals has the lowest energy? $4d, 4f, 5s, 5p$
$(b)$ Which of the following orbitals has the highest energy? $5p, 5d, 5f, 6s, 6p$