A student observes tiny pollen grains suspended in water under a microscope. The pollen grains are seen to move in a continuous, random, and jerky motion, known as Brownian motion.
Explain what causes this random motion of the pollen grains, referring to the particles involved.
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.