The term ________ is used to describe the ability of a substance to cause a harmful effect or damage to an organism, cell, or organ.

• A. Toxicity
• B. Reactivity
• C. Flammability
• D. Viscosity

Answer: (A)

Toxicity is the capacity of a substance to cause harm to living systems, including organisms, cells, or organs. This concept specifically captures how exposure to a chemical can lead to injury or disease, depending on factors like dose, route of exposure, and duration. That makes it the best description for describing a substance’s ability to cause harmful effects. The other terms refer to different properties: reactivity is about how readily a substance undergoes chemical reactions, flammability is about how easily it ignites, and viscosity describes how thick a liquid is or how it flows. None of those alone define the potential to cause harm to living tissue in the way toxicity does.