A student releases tiny pollen grains into a container of water and observes their movement under a microscope. Each pollen grain is seen to move in a highly irregular, random zigzag path.
State the term used to describe this random, zigzag motion.
Explain, in terms of the molecules of water, what causes this motion of the pollen grains.
321 exam-style questions on CIE IGCSE Physics 2.1 Kinetic particle model of matter, covering 2.1.1 States of matter and changes of state, 2.1.2a Particle structure and motion in solids, liquids and gases, 2.1.2b Gas pressure and particle collisions, 2.1.2c Brownian motion, 2.1.3a The absolute scale of temperature, and 2.1.3b Pressure, volume and temperature of a gas. Each one has a worked solution and a mark scheme showing where the marks go.