Question

Which type of matter needs to be separated by chemical methods ( breaking of bonds required ) such as electrolysis or decomposition

Answer 1

The correct answer is compound.  

The compounds comprise two or more elements, which are bonded together chemically, and can be dissociated, that is, distinguished by reforming and breaking the chemical bonds, by the decomposition reactions, like thermal decomposition or electrolysis. The process of decomposition generate simpler compounds or individual elements.