Chemical reactions of the elements
Reaction of tellurium with air
Tellurium burns in air to form the dioxide tellurium(IV) oxide, TeO2.
Te(s) + 2O2(g) → TeO2(s)
Reaction of tellurium with water
Tellurium does not react with water under normal conditions.
Reaction of tellurium with the halogens
Under carefully controlled conditions in a sealed tube, tellurium reacts with chlorine to form Te3Cl2.
Tellurium reacts with fluorine, F2, and burns to form the hexafluoride tellurium(VI) fluoride.
Te8(s) + 24F2(g) → 8TeF6(l) [orange]
Carefully done, tellurium reacts with fluorine, F2, mixed with nitrogen gas at 0°C to form the tetrafluoride tellurium(IV) fluoride. Tellurium also reacts under controlled conditions with the other halogens chlorine, Cl2, bromine, Br2, and iodine, I2, to form the respective tetrahalides tellurium(IV) chlrode, tellurium(IV) bromide, and tellurium(IV) iodide (requires heating).
Te8(s) + 16F2(g) → 8TeF4(s) 
Te8(s) + 16Cl2(g) → 8TeCl4(s) 
Te8(s) + 16Br2(g) → 8TeBr4(s) [red]
Te8(s) + 16I2(g) → 8TeI4(s) 
Reaction of tellurium with acids
Tellurium does not react with dilute non-oxidizing acids.
Reaction of tellurium with bases
Tellurium does not react with dilute bases under normal conditions.