Explain why the scientific method may not follow the exact same steps each time through the process.

The scientific method is the process used by scientists in the study of phenomena, in order to arrive at a reliable knowledge of the laws that govern them. The investigation in the context of science is done with specific and clearly defined procedures, which constitute the scientific method.

Thus, the scientific method uses a series of structured steps in order to reach said knowledge, moving from a first approximation to the subsequent hypothesis, the verification tests and a possible law that makes the knowledge acquired through a pattern effective.

Now, these systems of the scientific method are not always the same, but vary according to the specific needs of each question investigated, as science is a very broad field of study where each investigation covers very different questions from each other, with which the investigations will also be.

Learn more in link

a polymer is a chainlike molecule made up of small molecular units. these small molecular units are called monomers. monomers of polymer can be joined together either naturally or synthetically.  

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.