Which of the following is an example of a synthetic substance?

Plastics are a prime example of synthetic substances because they are artificially created through chemical processes, typically involving the polymerization of monomers derived from fossil fuels. Unlike natural substances that are found in nature, such as carbohydrates, fats, and minerals, which occur organically and can be derived from plants, animals, or geological processes, plastics are engineered materials designed for specific applications ranging from packaging to construction.

The classification of plastics as synthetic encompasses a wide variety of materials, including polyethylene, PVC, and nylon, all of which do not exist in nature and require human intervention to produce. This key characteristic of being man-made distinguishes plastics from substances like fats, which are organic compounds occurring in animals and plants, and carbohydrates, which are natural polymers produced by photosynthesis. Minerals, on the other hand, are naturally occurring inorganic solids that have specific chemical compositions and crystalline structures.

Thus, recognizing plastics as synthetic substances highlights the significant role of human innovation in material science, contrasting sharply with the natural origins of the other options listed.