General characteristic of group-15 elements:

(A) Electronic configurations :
The atoms of group 15 have five electrons in the outermost shell, two in s and three in p subshell. The general electronic configuration of this group may be expressed as ns² np³

(B) Oxidation state :
The elements of group-15 have five electrons in their valence shell. They exhibit various oxidation states from -3 to +5.

(i) The tendancy of the elements to exhibit – 3 oxidation state decreases on moving down from P to Bi due to increase in size and metallic character.

(ii) On moving down the group, the stability of + 5 oxidatioin state decreases while that of + 3 oxidation state increases due to inert pair effect.

(C) Atomic size:
The atomic and ionic radii of group-15 elements are smaller than the atomic radii of the elements of group 14 elements. On going down the group, the atomic radii increase with increase in atomic number.
Order of Atomic size :
N > P> As > Sb > Bi

(D) Electronegativity :
The electrogativity values of elements of group-15 are higher than the corresponding elements of group-14. On going down the group, the electronegativity value decrease.
Order of electronegativity given as :
N   > P >  As > Sb > Bi
(3.0) (2.1) (2.0) (1.9)  (1.9)