Final answer:
Liquids with a specific gravity of less than 1, being less dense than water, will float on the surface. This concept is based on density comparison, where a specific gravity below 1 indicates the substance is lighter than water and will not sink.
Step-by-step explanation:
When considering the behavior of liquids in relation to water, specific gravity is a critical factor. The specific gravity of a substance is a measure of its density compared to the density of water. If a liquid has a specific gravity of less than 1, it means that the liquid is less dense than water. Therefore, according to the principles of physics and buoyancy, a substance with a specific gravity less than 1 will float on the surface of the water. This can be observed with materials like oil, which is less dense than water and thus floats, creating a distinct separation between the two fluids.
Specific gravity is dimensionless and is independent of the units used for density. If the specific gravity is exactly 1, the object or substance will be neutrally buoyant in water, neither sinking nor floating. An example of this concept in practice is scuba divers who adjust their buoyancy to achieve a state where they can hover in the water without sinking or floating to the surface. Understanding specific gravity is also important in various applications such as checking the condition of fluids like battery acid, radiator fluid, and urine.