Question

Explain the factors that determine the electronegativity of a particular element, and describe why oxygen has a higher electronegativity than nitrogen and a higher electronegativity than chlorine.

Answer 1

Electronegativity is the ability of an atom in a bonded state to attract the shared electrons towards itself.

Although Electronegativity is not constant. Some factors which affect it are :

1)Generally increases across a period from left to right (say from lithium to flourine)

2)It decreases down a group (flourine to astatine)

3)Non metals have high tendency to gain electrons, thus high Electronegativity

4)Electronegativity is inversely related to metallic properties

5)It has almost similar trends like Ionization potential

Among O, N and Cl

Cl has largest size so lowest Electronegativity

Among N and O

N - outer configuration of 2p3

O-outer configuration of 2p4

As N has half filled orbital and it is more stable and it don't require extra electron.  

Thus O is more in need to gain an electron than N.

So Electronegativity of O is more than N.