Tellurium oxygen halogen compounds

The chemical properties of selenium fall between sulfur and tellurium. Thus, selenium reacts with oxygen similarly to sulfur, forming two oxides, selenium dioxide, Se02 and trioxide, SeOs. The metal combines with halogens forming their halides. With nonmetals, selenium forms binary compounds exhibiting oxidation states +4 and -i-6. 

General Properties of Compounds of Cobalt—Cobalt and the Halogens—Oxy-Halogon Derivatives—Cobalt and Oxygen—Cobalt and Sulphur—The Alums—Cobalt and Selenium, Tellurium, Chromium, and Molybdenum—... 

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