A product that sinks in water has a higher what property than water?

• A. Flammability
• B. Boiling point
• C. Viscosity
• D. Specific gravity

Answer: (D)

When something sinks in water, it means its density is greater than water’s. The property that compares density to water is specific gravity. Specific gravity is the ratio of the material’s density to the density of water (water is defined as 1.0). If this ratio is greater than 1, the substance will sink; if it’s less than 1, it will float. In practice, water’s density is about 1 g/cm3, so any product with a specific gravity above 1 will sink. The other properties listed—flammability, boiling point, and viscosity—describe ignition risk, the temperature at which it becomes vapor, and how thick or sticky it is, but they don’t determine whether the liquid will sink or float.