PSI Barbering Practice Exam

What is the primary distinction between organic and inorganic substances?

1. Presence of carbon

2. Presence of hydrogen

3. Natural vs. synthetic

4. Solubility in water

The correct answer is: Presence of carbon

The primary distinction between organic and inorganic substances lies in the presence of carbon. Organic substances are defined by the presence of carbon atoms, typically bonded with hydrogen, oxygen, nitrogen, and other elements. This carbon-based characteristic is what sets organic compounds apart, as they generally include a wide variety of molecules such as carbohydrates, proteins, lipids, and nucleic acids that are crucial for life. In contrast, inorganic substances are typically defined as those that do not contain carbon-hydrogen (C-H) bonds, although there are exceptions, such as carbonates and certain carbon oxides, which are still considered inorganic. Understanding this distinction is foundational in chemistry and helps in classifying compounds and predicting their properties and behaviors in various contexts, including in the field of barbering for understanding the materials and products used, like certain chemicals. The other options, while potentially relevant in specific contexts, do not serve as defining characteristics for the distinction between organic and inorganic substances. Natural vs. synthetic speaks more to the origin of substances rather than their chemical classification, while solubility in water can vary widely within both organic and inorganic categories. Presence of hydrogen is also not exclusive, as both organic and inorganic compounds can contain hydrogen. Ultimately, the presence of carbon is the