Viscosity - GCSE Chemistry Definition

Viscosity is a measure of how thick or sticky a liquid is and how easily it flows. Imagine pouring honey and water: honey flows much slower than water because it is more viscous. Viscosity depends on the internal friction within the liquid, which is how much the liquid’s molecules resist moving past one another. Liquids with high viscosity, like syrup, flow slowly, while those with low viscosity, like water, flow quickly. Understanding viscosity helps us to explain why some liquids run faster or slower, and is important in both everyday life and in scientific experiments.