Electronegativity of aluminium is 1.5. Electronegativity of thallium is

detailed solution

Correct option is B

Electronegativity order :B > Tl >In > Ga > AlTl  Electronegativity is greater than that of Al,Given Al Electronegativity is 1.5,hence Tl Electronegativity  should be greater than that of 1.5.Greater than 1.5 two options are there ,those are second and fourth options .On pauling scale highest Electronegativity element is F,its Electronegativity value is on Pauling scale is 4.0.Therefore fourth option is wrong.Then option 2 is correct.