- LiF
Explanation:
Lithium is an alkali metal and it is electro-positive in nature.
The order of electronegativity of halides present in these compounds are as follow:
F > Cl > Br > I
Hence, lithium fluoride (LiF) is the most stable compound because of the small size of Li.
As we go down the group in the periodic table the size of the element increases so, the Li−X bond becomes weak.
As Li and F are of comparable size that is why LiF is the most stable.
Also, LiF has the highest lattice enthalpy.