how are chemical compounds formed
Reactions and compounds. New substances are formed by chemical reactions. When elements react together to form compounds their atoms join to other atoms using chemical bonds. For example, iron and sulfur react together to form a compound called iron sulfide.Mixture of iron (grey) and sulfur (yellow) powders.Compounds usually have different properties from the elements they contain.hen elements react together to form compounds their atoms join to other atoms using chemical bonds. For example, iron and sulfur react together to form a compound called iron sulfide. Mixture of iron (grey) and sulfur (yellow) powders. Compounds usually have different properties from the elements they contain.