Understanding Hydrometer Behavior in Different Liquid Densities

An image of a hydrometer floating in three separate transparent containers filled with different liquids. The first container holds clear water (freshwater), the second holds salty water (saltwater), and the third holds oil. The hydrometer sinks the most in the oil, floats higher in the saltwater, and floats the least in the freshwater. The liquids have clear labels, and the hydrometer is visible in all three containers with varying levels of immersion based on the density of each liquid