Using electronegativity differences, arrange the following four compounds in order of increasing ionic compound:
kbr,
alcl3,
li2o,
nai,
hf

AlCl₃ < NaI < HF < KBr < Li₂O

Explanation:

Electronegativity difference may help you to predict the sort of bond in a compound. We have to search for the electronegativity in the Periodic table and then, make a subtraction.

ΔEN = 0 → covalent bond, non polar

0 < ΔEN < 1.7 → covalent bond, polar

ΔEN ≥ 1, 7 → ionic bond

KBr → 3 - 0.8 ⇒ ΔEN = 2.2

AlCl₃→ 3.2 - 1.6 ⇒ ΔEN = 1.6

Li₂O → 3.4 - 1 ⇒ ΔEN = 2.4

NaI → 2.7 - 0.9 ⇒ ΔEN = 1.8

HF → 4 - 2.1 ⇒ ΔEN = 1.9