Why the stability of following metal chloride follows the order

LiCl>KCl>NaCl>CsCl

Please explain in detail.

Electronegativity of Lithium (Li) is 1.0,Sodium (Na) is 0.9,Potassium(K) is 0.8,Casium (Cs) is 0.7 and Chlorine is 3.0.

Note -Electronegativity increases from LEFT to RIGHT in Periodic Table and decreases from TOP to BOTTOM.....

If difference between electronegativities of two elements are more then they are more unstable....and if less they are more stable.

1.Difference between Cs and Cl is 2.3 so Most Unstable.
2.Difference between K and Cl is 2.2 so more stable than CsCl.
3.Difference between Na and Cl is 2.1 so more stable than KCl.
4.Difference between Li and Cl is 2 so most stable among Four.

and then it is---LiCl>NaCl>KCl>CsCl.