How many orbitals are there in $\mathrm{K},\mathrm{L},\mathrm{M}$ and $\mathrm{N}$ shells? What are they? 

Identify the sets of quantum numbers which are not possible?

$$\begin{gathered} \mathrm{a}. \mathrm{n}=0, \mathrm{l}=0, {\mathrm{m}}_1= 0, {\mathrm{m}}_{\mathrm{s}}= +\frac{1}{2} \\ \mathrm{b}. \mathrm{n}=1, \mathrm{l}=0, {\mathrm{m}}_1= 0, {\mathrm{m}}_{\mathrm{s}}= -\frac{1}{2} \\ \mathrm{c}. \mathrm{n}=1, \mathrm{l}=1, {\mathrm{m}}_1= 0, {\mathrm{m}}_{\mathrm{s}}= +\frac{1}{2} \\ \mathrm{d}. \mathrm{n}=2, \mathrm{l}=1, {\mathrm{m}}_1=0, {\mathrm{m}}_{\mathrm{s}}=-\frac{1}{2} \end{gathered}$$

Two atoms are said to be isobars if 

Match the following :
List -I :
(a) Frequency of distribution of the emitted radiation from a black body
(b) Spin quantum numbers(m_s)
(c) Angular Momentum
(d) All orbital have equal energy

List - II :
(i) degeneracy
(ii) temperature dependent
(iii) vector quantity
(iv) mass times velocity times radius 

Codes:

Nitrogen (atomic number $7$) and phosphorus (atomic number $15$) belong to group $15$  of the Periodic Table. Write the electronic configuration of these two elements. Which one of these will be more electronegative? Why?