How can components of a mixture generally be separated?

Correct answer: By physical methods

The direct answer is C: components of a mixture can generally be separated by physical methods. A mixture contains two or more substances that are combined without forming a new chemical substance. Because the original substances retain their own properties, differences such as particle size, boiling point, solubility, density or magnetism can be used for separation. For example, filtration separates an insoluble solid from a liquid, evaporation recovers a dissolved solid, and distillation separates liquids with different boiling points. Option C is correct. A is wrong because nuclear reactions are not the normal way to separate mixtures and change atomic nuclei. B is wrong because mixtures can often be separated. D is wrong because making new elements is neither necessary nor a method of ordinary mixture separation. A useful distinction is that physical separation does not normally change chemical identities, whereas a chemical reaction forms new substances. Exam cue: mixture means separation by physical properties.