Final answer:
The order of increasing conductivity is Te, He, Tl.
Step-by-step explanation:
The correct answer is Te, He, Tl.
Conductivity is a measure of how well a substance conducts electricity. In general, metals are good conductors of electricity, while nonmetals are poor conductors. Among the given elements, Te (tellurium) is a metalloid, He (helium) is a nonmetal, and Tl (thallium) is a metal.
Since metals have high conductivity compared to nonmetals, the order of increasing conductivity is Te (the highest), He, and Tl (the lowest).
Learn more about conductivity of elements