Given that chemical changes is a form of change of matters that deal with the combination of various substances to form a new substance entirely that has different chemical and physical characteristics from its parents' substances.
Hence, when Animal waste is acted upon by anaerobic bacteria to produce biogas it is considered a chemical change.
Similarly, when biogas burnt as fuel it is also considered as a chemical change.
Therefore, in this case, the correct answer is "Both Change A and B" are chemical changes.
According to modern classification I will say that Jake is correct. With the use of tracing back and DNA technology then we can say that this is the digital way which is used nowadays to classify animals.
Sophie says through her observation that the characteristics of the animal classification used.
