Electronegativity:- Tendency to attract the shared pair of electron towards one of the combining atom in a covalently bonded molecule?

Periods	Groups
Trend:- Along the periods it increases Reason:- Size decreases.	Trend:- Along the groups it decreases  Reason:- Size increases.

 

Important (1) F is the most negative electronegative element in the periodic table, (F – 4.0)

(2)  N – 3.0

(3) Electronegativity is measured on Pauling / Mulliken scale etc.

 E^Θ negativity of N is 3.0 and it does not remain same in all of its compounds because if depends upon the type of hybridization and the nature of other element attached