Water is denser than kerosene. The density of water at standard temperature (20°C) is approximately 0.998 g/cm³, while kerosene typically has a density ranging from 0.82 to 0.84 g/cm³. This difference arises from molecular composition and intermolecular forces. Water’s high density stems from its polar structure and hydrogen bonding, which allow molecules to pack closely. Kerosene, a nonpolar hydrocarbon mixture, exhibits weaker London dispersion forces, leading to looser molecular packing and lower density. For example, the U.S. National Institute of Standards and Technology (NIST) reports water’s density as 0.9982 g/cm³ at 20°C, whereas kerosene’s density averages 0.820 g/cm³ under similar conditions. The density contrast explains why water and kerosene form distinct layers when mixed, with water settling below kerosene. This principle is critical in applications like fuel storage, where separation by density prevents mixing. Data from the American Chemical Society further confirms that kerosene’s density decreases with increasing temperature, unlike water, which remains relatively stable. Thus, water’s higher density is a fundamental physical property rooted in its molecular interactions and structural integrity.