What does a specific gravity less than 1 indicate about a substance's behavior in water?

• A. It sinks in water
• B. It dissolves in water
• C. It floats on water
• D. It evaporates in water

Answer: (C)

A specific gravity less than 1 indicates that a substance is less dense than water. When a substance has a specific gravity below this threshold, it means that its density is lower than that of water, resulting in the substance floating rather than sinking. This principle is based on the relationship between density and buoyancy, where an object will float on a liquid if it is less dense than that liquid. Therefore, a specific gravity of less than 1 leads to the conclusion that the substance will float on water, which aligns perfectly with the correct answer. Understanding this concept is crucial in various scenarios, especially in hazardous materials situations where the behavior of substances in water can inform safety measures and emergency responses.