Viscosity

Abstract

Viscosity measures the thickness or resistance of a liquid to flow. It originates from the word "viscous," describing a material that softens and flows slowly when heated. Viscosity reflects the internal movement of fluid layers, influenced by intermolecular attraction forces. Liquids with strong intermolecular forces exhibit high viscosity, causing slow flow, like glycerin, castor oil, and honey. In contrast, low-viscosity liquids such as water, alcohol, and gasoline flow quickly. Viscosity depends on temperature, molecular attraction, and the size and number of dissolved molecules. As temperature rises, viscosity decreases because molecules move more freely. Fluids, both liquids and gases, have molecules spaced variably, not fixed in lattices, allowing free movement. The viscosity coefficient varies with fluid type, molecular interactions, and temperature. Observations showed water’s viscosity as 3.0 × 10⁻² Ns/m², cooking oil 7.2 × 10⁻³ Ns/m², sunlight 7.6 × 10⁻² Ns/m², and alcohol 3.1 × 10⁻⁴ Ns/m². Sunlight exhibited the highest viscosity compared to oil, alcohol, and water, indicating its greater resistance to flow.