Metal halides are compounds between metals and halogens. The hydrogen-halogen reactions get gradually less reactive toward the heavier halogens. Compounds containing halogens (especially chlorine and bromine) can produce very distinct isotope peaks. Ethane can react with the halogens, especially chlorine and bromine, by free radical halogenation. Metal sulfides react with halogens, forming sulfur and metal salts. Common oxidizing agents are oxygen, hydrogen peroxide and the halogens. Polyhalogenated compounds are industrially created compounds substituted with multiple halogens. CPVC is resistant to many acids, bases, salts, paraffinic hydrocarbons, halogens and alcohols. Halogens and chalcogens can also form halochalcogenate anions. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. All of the halogens form acids when bonded to hydrogen. Interhalogen compounds contain at most two different halogens. Most bonds to iodine are weaker than the analogous bonds to the lighter halogens. Nickel forms simple binary compounds with non metals including halogens, chalcogenides, and pnictides. It also reacts with the other halogens and absorbs hydrogen.